Patent Description:
The present invention generally relates to supports for handling and embedding tissue samples for pathological analysis and, more particularly, to microtome sectionable supports which can receive one or more tissue samples and a support frame having a tissue immobilizing lid.

To accurately diagnose various tissue diseases and conditions, medical personnel must remove one or more samples of tissue from the body of a patient. This process of harvesting tissue from the body is known as a biopsy. Once the tissue sample or samples are removed and sent to a pathology laboratory, the tissue will go through a series of procedures performed by a histotechnician and, ultimately, a pathologist, in order to diagnose one or more conditions associated with the tissue. The present invention generally relates to those procedures that are normally performed by the histotechnician to prepare the tissue sample or samples into slides that may be analyzed under a microscope by the pathologist.

Although the singular term "sample" is used throughout this specification, it should be understood that this term likewise encompasses plural "samples" as well. Once a tissue sample is removed from the body of a patient, it is typically placed into a specimen container containing a tissue fixative solution and then the container is transported to a pathology laboratory. The tissue will undergo a process known as "grossing-in" in the pathology lab during which a histotechnician will retrieve the tissue sample from the container, typically cut the tissue into appropriate sizes for tissue processing, place individual samples into the appropriate sized small plastic tissue cassettes, and assign tracking numbers to each cassette. The assignment of tracking numbers is usually done by printing the tracking number on the cassette, or onto a label which is then applied to the cassette. These tracking numbers are then logged into a tracking system used in the laboratory. For the smallest tissue samples, which may only be scrapings, the cassette includes fine mesh openings on the sides and bottoms. In other situations involving very small tissue samples, the samples are placed into a bag that resembles a tea bag that prevents the smallest tissue samples from escaping. Larger tissue samples are placed into cassettes having somewhat larger slotted openings which are nevertheless smaller than the tissue sample inside the cassette.

The cassettes are then placed into a stainless steel perforated basket and run through a tissue processing machine, often overnight. This machine uses a combination of vacuum, heat, and liquid reagents or chemicals to remove the interstitial fluids within the tissue. Once the fluids have been removed from the tissue samples, the processing machine immerses the tissues samples in a bath of a hardenable material such as molten paraffin (i.e., a form of wax) so that the interstices in the tissue are replaced with paraffin. The histotechnician then removes the basket from the machine and removes the individual tissue cassettes. In a conventional procedure practiced for many years, the histotechnician individually removes the tissue sample from each cassette. The histotechnician must carefully orient the tissue sample, based on tissue type, into a stainless steel base mold that is roughly the size of the tissue cassette and is partially filled with molten paraffin. The tissue sample must be manually held, typically using forceps, against the bottom of the mold. If it is not, this could compromise the ability to make proper slices of the tissue sample later in a microtome. The molten paraffin is then rapidly cooled on a refrigerated plate, which may be a thermal electric cooler (TEC), to partially solidify the paraffin thereby holding the tissue sample in the proper orientation against the bottom of the mold.

The cassette is then placed on top of the base mold and an embedding material, which is also typically paraffin wax, is poured through the opened top of the cassette into the base mold. The cassette changes its function at this point in the procedure from a tissue holding component to a fixture type device for mounting in the microtome and making shavings or slices from the solidified paraffin block (containing the tissue sample) in the microtome. The base mold is chilled until all of the molten paraffin has hardened and the histotechnician removes the stainless steel base mold from the block of paraffin and embedded tissue. The tissue sample is thus embedded within a rectangular block of hard paraffin with a plastic tissue cassette on the opposite side. As mentioned, the cassette may then be used as a holder or fixture in the chuck of the microtome. As with the tissue processing machine, the embedding process is accomplished in a batch fashion during which an average histotechnician may process approximately <NUM> to <NUM> cassettes per hour into blocks of embedded tissue.

The blocks of hardened paraffin containing the embedded tissue samples are then ready to be sliced into extremely thin sections for placement on a microscope slide. The histotechnician mounts the embedded tissue block in a chuck on the microtome sized to accept the side of the block that has the embedded plastic cassette. The histotechnician can then begin slicing the paraffin block which has the tissue sample embedded opposite to the plastic cassette surface. This yields a ribbon of individual slices of the tissue embedded in the hardened paraffin. The action of the microtome causes the individual slices to stick together when done properly and, subsequently, these very thin ribbons of slices are floated into a water bath and a glass slide is carefully placed underneath the slice. Each slice, with the thin sectioned tissue sample embedded therein, is then adhered to the top of a microscope slide. When the histotechnician has enough slides from the tissue sample, the slides are placed into an automatic staining machine. The staining machine goes through a series of infiltrating steps to stain the different tissue and cells of the slide different colors. This helps the pathologist identify different structures and makes it easier to find any abnormalities in the tissue. After the staining procedure is complete, the slides are cover slipped and prepared for the pathologist to place under a microscope for analysis.

Based on the summary of the procedure provided above, it will be appreciated that conventional tissue sample handling and processing is a very labor-intensive process involving several manual steps performed by a histotechnician. Thus, repetitive stress injuries such as carpal tunnel syndrome are prevalent. This is especially true with the tissue sample embedding process. These multiple manual operations and repeated tissue handling increase the likelihood of human error and, moreover, require highly trained and skilled histotechnicians to ensure that the tissue samples ultimately adhered to the slides for analysis by the pathologist are in an optimum condition and orientation to make accurate diagnoses.

<CIT> (the '<NUM> patent),<CIT>, <CIT>,<CIT>,<CIT> and <CIT>and <CIT> disclose various improvements to this area of technology, including new manners of holding tissue samples during the grossing in, embedding, and microtome or slicing procedures. For example, the '<NUM> patent relates to a tissue trapping and supporting device, which may be a cassette, and which may be successfully sectioned using a microtome. When such a cassette is used, the tissue sample is immobilized within the cassette and subjected to the process for replacing tissue fluids with paraffin. Then, both the tissue sample and the cassette are sliced at the same time for later mounting on microscope slides. Because the tissue sample is never removed from the cassette from the time it is processed in the tissue processing machine to the time that it is cut or sliced with the microtome, a significant amount of handling time is saved. Moreover, the chance for human error or tissue loss is significantly reduced due to the elimination of separate tissue handling steps. The '<NUM> patent also generally discloses further improvements that help to automate the overall process and, in conjunction with the novel tissue supports (e.g., cassettes), can even further reduce the handling steps during the entire procedure and make the procedure more reliable. <CIT> discloses a cassette system for harvesting and handling tissue samples for biopsy analysis. The cassette system may comprise a cassette and a frame, and the cassette may include a plurality of slots defined in a cassette wall and which accommodate corresponding projections on the frame to hold the cassette in place in the frame.

Various drawbacks of current procedures and limits on innovation exist. For instance, improvements to the outer form of the cassette and frame are bounded by existing limits of histopathology lab equipment such as tissue processing retorts, and "input devices" for tissue processors, embedding stations, printers, and microtomes. Many of these processes are integrated with systems and machines for automation of the steps and robotic handling further limiting the potential for innovation. Additionally, costs for materials have been rising in recent years, especially for the fluoropolymer (FEP/PFA) sectionable plastics useful in sectionable cassettes. Each cassette is essentially consumed by the sectioning procedure, which adds to the cost of the pathology procedure. Further, because the sectionable FEP/PFA material is not rigid, it may be utilized for some components (e.g., the cassette), while other components (e.g., frames) may be constructed from harder or more rigid materials.

In spite of the various advances made in this field, there is a need for additional improvements related to cassettes and embedding frames, particularly for cassette and frame assemblies including some components formed of relatively soft materials (e.g., sectionable plastics) that are coupled to other components formed of harder materials.

In accordance with the invention, a histologic tissue sample support device according to claim <NUM> includes a tissue cassette having a recess including at least one side wall and a bottom wall. The tissue cassette is formed of a first material that can be successfully sectioned in a microtome and is resistant to degradation from solvents and chemicals used to fix, process and stain tissue. The device further includes a frame including a bottom edge, the frame formed of a second material different from the first material and more rigid than the first material. The tissue cassette is coupled to the frame by a frame-cassette connector including a first retaining structure formed integrally with the frame and extending at least partway through a second retaining structure formed integrally with the cassette. The device further includes a lid coupled to the frame. The lid and the tissue cassette are capable of moving from a first position to a second position with respect to the frame. In the second position, the bottom wall and at least a portion of the side wall extend downwardly beyond the bottom edge of the frame for sectioning in the microtome. The frame is capable of being decoupled from the cassette by separating the frame-cassette connector.

In additional or alternative embodiments, the first retaining structure may include a pin formed integrally with the frame. The second retaining structure may include a flange formed integrally with the cassette. Moving the lid and the tissue cassette from the first position to the second position may break the flange formed integrally with the cassette. The flange formed integrally with the cassette may include a stress riser arranged to encourage breakage of the flange formed integrally with the cassette when the lid and the tissue cassette are moved from the first position to the second position. The frame may include a plurality of outer walls extending generally upward from the bottom edge. The pin formed integrally with the frame may be disposed on a tab extending generally laterally inwardly from one of the plurality of outer walls. The pin formed integrally with the frame may extend generally upwardly from the tab. The pin formed integrally with the frame may extend generally downwardly from the tab. The tab extending from one of the plurality of outer walls may be pivotably coupled to the one of the plurality of outer walls. The pin formed integrally with the frame may have a generally circular cross section. The pin formed integrally with the frame may include a base, a tip having a tip width, and a shaft having a shaft width and extending from the base to the tip, and the tip width may be greater than the shaft width.

In additional or alternative embodiments, the lid may be coupled to the frame by a lid-frame connector comprising a third retaining structure formed integrally with a peripheral portion of the frame extending at least partway through a fourth retaining structure formed integrally with the lid. The lid may be capable of being decoupled from the peripheral portion of the frame by separating the lid-frame connector. The third retaining structure may include a pin formed integrally with the peripheral portion of the frame. The fourth retaining structure may include a flange formed integrally with the lid. Moving the lid and the tissue cassette from the first position to the second position may break the flange formed integrally with the lid. The lid may be formed of the first material. The peripheral portion of the frame may include a plurality of peripheral walls surrounding the lid. The pin formed integrally with the peripheral portion may be disposed on a tab extending generally laterally inwardly from one of the plurality of peripheral walls. When the lid is in a closed configuration, the pin formed integrally with the peripheral portion may extend generally downwardly from the tab. When the lid is in a closed configuration, the pin formed integrally with the peripheral portion may extend generally upwardly from the tab. The tab extending from one of the plurality of peripheral walls may be pivotably coupled to the one of the plurality of peripheral walls. The pin formed integrally with the peripheral portion may have a generally circular cross section.

In additional or alternative embodiments, the tissue cassette may include a cassette closure element and the lid may include a lid closure element, the cassette closure element and the lid closure element being configured, when engaged, to secure the lid to the tissue cassette. One of the cassette closure element and the lid closure element may include a first connector disposed on a first extending arm and the other of the cassette closure element and the lid closure element may include a second connector, the first connector engaging the second connector to secure the lid to the tissue cassette. The lid closure element may include the first connector disposed on the first extending arm and the cassette closure element may include the second connector. The lid closure element may include a third connector disposed on a second extending arm, the first extending arm and the second extending arm projecting generally downwardly from the lid when the lid is in a closed configuration on the cassette, the first extending arm and the second extending arm disposed on the lid in a spaced-apart, opposed arrangement such that the first connector faces away from the third connector. The cassette closure element may include a fourth connector arranged to engage the third connector, the second connector and the fourth connector being generally laterally oriented.

In additional or alternative embodiments, the lid closure element may include a third connector disposed on a second extending arm, the first extending arm and the second extending arm projecting generally downwardly from the lid when the lid is in a closed configuration on the cassette, the first extending arm and the second extending arm disposed on the lid in an opposed arrangement such that the first connector faces towards the third connector. The second connector may be oriented generally laterally and may be arranged to engage the first connector and the third connector. The frame may include a plurality of outer walls extending generally upward from the bottom edge and a peripheral portion coupled to one of the plurality of outer walls by a hinge. The tissue cassette may be coupled to one of the plurality of outer walls and the lid may be coupled to the peripheral portion. At least one of the plurality of outer walls may include a frame closure element and the peripheral portion may include a peripheral portion closure element, the frame closure element and the peripheral portion closure element being configured, when engaged in a closed configuration, to secure the peripheral portion to the plurality of outer walls. One of the frame closure element and the peripheral portion closure element may include a latch disposed on an extending arm and the other of the frame closure element and the peripheral portion closure element may include a flange, the latch engaging the flange to secure the peripheral portion to the plurality of outer walls in the closed configuration. The peripheral portion closure element may include the latch disposed on the extending arm and the frame closure element may include the flange. The extending arm may project generally downwardly from the peripheral portion in the closed configuration and the flange may be oriented generally laterally.

In additional or alternative embodiments, the lid may include a platen configured to be received within the recess of the tissue cassette, the platen being mounted to a peripheral portion of the lid by a plurality of biasing members arranged to bias the platen toward the bottom wall of the recess when the lid is in a closed configuration. The biasing members may be disposed in at least one of a generally helical arrangement and a generally perpendicular arrangement between the platen and the peripheral portion of the lid.

In accordance with another embodiment not according to the present invention, a histologic tissue sample support device includes a tissue cassette having a recess including at least one side wall and a bottom wall. The tissue cassette is formed of a first material that can be successfully sectioned in a microtome and is resistant to degradation from solvents and chemicals used to fix, process and stain tissue. The device further includes a frame including a bottom edge. The tissue cassette is movably coupled to the frame. The device further includes a lid coupled to the frame. The lid includes a platen configured to be received within the recess of the tissue cassette. The platen is mounted to a peripheral portion of the lid by a plurality of biasing members arranged to bias the platen toward the bottom wall of the recess when the lid is in a closed configuration. The lid and the tissue cassette are capable of moving from a first position to a second position with respect to the frame. In the second position, the bottom wall and at least a portion of the side wall extend beyond the bottom edge of the frame for sectioning in the microtome.

In additional or alternative embodiments not according to the present invention, the biasing members may be disposed in a generally helical arrangement between the platen and the peripheral portion of the lid. The biasing members may be disposed in a generally perpendicular arrangement between the platen and the peripheral portion of the lid. The platen may include a plurality of tines extending toward the bottom wall of the recess when the lid is in the closed configuration. The lid may be formed of the first material. The frame may be formed of a second material different from the first material and more rigid than the first material, the tissue cassette being coupled to the frame by a frame-cassette connector comprising a first retaining structure formed integrally with the frame extending through a second retaining structure formed integrally with the cassette. The first retaining structure may include a pin formed integrally with the frame and the second retaining structure may include a flange formed integrally with the cassette. The lid may be coupled to the frame by a lid-frame connector comprising a first retaining structure formed integrally with a peripheral portion of the frame extending at least partway through a second retaining structure formed integrally with the lid. The lid may be capable of being decoupled from the peripheral portion of the frame by separating the lid-frame connector. The first retaining structure may include a pin formed integrally with the peripheral portion of the frame. The second retaining structure may include a flange formed integrally with the lid.

The invention further provides a method not according to the present invention for manufacturing an apparatus for holding a histologic tissue sample while sectioning the tissue sample in a microtome. The method includes molding a tissue cassette having a recess including at least one side wall and a bottom wall, the tissue cassette being formed of a first material that can be successfully sectioned in a microtome and is resistant to degradation from solvents and chemicals used to fix, process and stain tissue. The method further includes molding a frame including a bottom edge, the frame being formed of a second material different from the first material and more rigid than the first material. The method further includes coupling the tissue cassette to the frame by assembling a frame-cassette connector comprising a first retaining structure formed integrally with the frame extending at least partway through a second retaining structure formed integrally with the cassette. The cassette is capable of being decoupled from the frame by separating the frame-cassette connector.

In additional or alternative embodiments not according to the present invention, the first retaining structure may include a pin formed integrally with the frame. The second retaining structure may include a flange formed integrally with the cassette. Assembling the frame-cassette connector may include forming a mushroom head shaped tip on the pin formed integrally with the frame to secure the flange formed integrally with the cassette on the pin formed integrally with the frame. Forming the mushroom head shaped tip on the pin may include deforming the pin to form the mushroom head shaped tip. Deforming the pin to form the mushroom head shaped tip may include using a tool to form the mushroom head shaped tip when the pin is at a temperature above room temperature and below a melting temperature of the second material. Assembling the frame-cassette connector may include at least one of (<NUM>) assembling separately molded components, (<NUM>) co-molding the frame and the cassette, and (<NUM>) insert molding the frame and the cassette. The method may further include molding a lid; and coupling the lid to the frame by assembling a lid-frame connector comprising a third retaining structure formed integrally with a peripheral portion of the frame extending through a fourth retaining structure formed integrally with the lid. The lid may be capable of being decoupled from the peripheral portion of the frame by separating the lid-frame connector. The third retaining structure may include a pin formed integrally with the peripheral portion of the frame. The fourth retaining structure may include a flange formed integrally with the lid. Assembling the lid-frame connector may include at least one of (<NUM>) assembling separately molded components, (<NUM>) co-molding the lid and the frame, and (<NUM>) insert molding the lid and the frame.

The invention further provides a method for preparing one or more biopsy tissue samples for histological examination according to claim <NUM>. The method includes positioning a tissue sample in a tissue cassette having a recess including at least one side wall and a bottom wall, the tissue cassette formed of a first material that can be successfully sectioned in a microtome and is resistant to degradation from solvents and chemicals used to fix, process and stain tissue, the tissue cassette being disposed in a frame including a bottom edge, the tissue cassette being coupled to the frame by a frame-cassette connector including a first retaining structure formed integrally with the frame extending through a second retaining structure formed integrally with the cassette. The method further includes closing a peripheral portion of the frame, the peripheral portion of the frame including a cassette lid disposed therein. The method further includes moving the lid and the tissue cassette from a first position to a second position with respect to the frame including breaking the frame-cassette connector. In the second position, the bottom wall and at least a portion of the side wall extend downwardly beyond the bottom edge of the frame for sectioning in the microtome.

In additional or alternative embodiments, the first retaining structure may include a pin formed integrally with the frame. The second retaining structure may include a flange formed integrally with the cassette. The moving operation may include breaking a lid-frame connector including a third retaining structure formed integrally with the peripheral portion of the frame extending through a fourth retaining structure formed integrally with the lid. The third retaining structure may include a pin formed integrally with the peripheral portion of the frame. The fourth retaining structure may include a flange formed integrally with the lid. The frame may be formed of a second material different from the first material and more rigid than the first material; and the lid may be formed of the first material. The closing operation may include securing the tissue sample in the recess using a platen mounted to the lid by a plurality of biasing members arranged to bias the platen toward the bottom wall of the recess.

Various additional features and advantages of the invention will become more apparent to those of ordinary skill in the art upon review of the following detailed description of the illustrative embodiments taken in conjunction with the accompanying drawings.

Referring first to <FIG>, <FIG>, and <FIG>, an assembly <NUM> constructed in accordance with an illustrative embodiment of the invention is shown in the open position. Assembly <NUM> includes a tissue sample cassette <NUM> carried within and separably coupled to a frame <NUM>, which includes a peripheral portion <NUM>. A lid <NUM> is separably coupled to peripheral portion <NUM>. While cassette <NUM> is shown to have a rectangular configuration, it will be recognized that cassette <NUM> may have alternative configurations. For example, a cassette may have a circular configuration. Peripheral portion <NUM> generally includes an interior <NUM> defined between surrounding (peripheral) side walls 16a, 16b, 16c, 16d, and lid <NUM> is sized and configured to fit in the interior and is separably coupled to at least one of the surrounding walls 16a, 16b, 16c, 16d. The frame <NUM> generally includes an interior defined between surrounding outer walls 14a, 14b, 14c, 14d and a bottom edge 14e, and the cassette <NUM> is sized and configured to move within the interior between at least first and second positions. The first position is shown in <FIG> and <FIG>, while the second, "staged" position is shown in <FIG>. In the second position, the lower portion of the cassette <NUM> is exposed below the bottom edge 14e of the frame <NUM> for allowing cassette <NUM> and an embedded tissue sample <NUM> to be sectioned in a microtome while the frame <NUM> is held in the microtome chuck.

The cassette <NUM> may be coupled to the frame <NUM> in manners such as described hereinbelow. In the illustrative embodiment of <FIG>, cassette <NUM> is initially separably coupled to frame <NUM> through frame-cassette connectors <NUM> that couple the surrounding walls 14a, 14b, 14c, 14d to the cassette <NUM>.

Referring to <FIG> and <FIG>, each frame-cassette connector <NUM> includes a retaining structure (e.g., first retaining structure), such as a pin <NUM>, formed integrally with the frame <NUM> and extending at least partway through a retaining structure (e.g., second retaining structure), such as a flange <NUM> formed integrally with the cassette <NUM>, such as on a sidewall 12a of cassette <NUM>. Each pin <NUM> extends generally upwardly from a tab <NUM>, which extends generally laterally inwardly from one of the outer walls 14a, 14b, 14c, 14d. Pin <NUM> includes a base <NUM> disposed on tab <NUM>, a tip <NUM> on an opposite surface of flange <NUM>, and a shaft <NUM> extending from the base <NUM> to the tip <NUM> through flange <NUM>. Tip <NUM> may have a tip width <NUM> that is greater than a shaft width <NUM>. Generally, because the tip <NUM> and the tab <NUM> are wider than the shaft <NUM>, and because the flange <NUM> extends within the recessed or undercut area between the tip and the tab, the flange is retained on the pin <NUM> by the tip and the tab. Accordingly, until the frame-cassette connector <NUM> is separated (e.g., broken) during the staging operation as discussed in greater detail below, the flange <NUM> is secured to the pin <NUM>. Pin <NUM> may be formed as a right circular cylinder or conical frustrum have a generally circular cross section. In this illustrative embodiment, the first retaining structure is a pin <NUM>, but it will be understood that in other embodiments the first retaining structure may take other forms, such as any shape or structure configured to extend at least partway through a corresponding second retaining structure (e.g., the flange <NUM> formed integrally with the cassette <NUM>) to attach or couple two or more components. Such first retaining structures may include, for example and without limitation, a peg, a bar, a shaft, a stem, a stick, etc., and may have any cross-sectional shape, such as generally circular, generally oval, or generally polygonal (e.g., generally square, pentagonal, hexagonal, etc.). Additionally, a first retaining structure may be generally straight or may include one or more curves, bends, or angles.

Referring to <FIG> (first position) and 4C (second position), frame-cassette connectors <NUM> of this illustrative embodiment are frangible and are configured to break when cassette <NUM> is moved from the first position toward the second position. In the illustrative embodiment, pin <NUM> tears out of flange <NUM>, breaking flange <NUM>, during this movement. In other embodiments with different relative sizes or material choices for pin <NUM> and flange <NUM>, pin <NUM> or tab <NUM> may break before pin <NUM> tears out of flange <NUM>. In other embodiments, various connectors, such as frame-cassette connectors and lid-frame connectors (discussed below), may be configured to separate without breaking. For example, some connectors may be configured to accommodate sufficient elastic deformation to allow a pin to be removed from a flange without breakage of the pin, the tab, or the flange. Returning to the illustrative embodiment, as can be seen by comparing the orientation of tabs <NUM> <FIG> and <FIG>, each tab <NUM> may be pivotably coupled to its respective outer wall 14a, 14b, 14c, 14d so that, during movement from the first position to the second position, tab <NUM> pivots downward, which may encourage predictable and consistent separation (e.g., breakage) of frame-cassette connector <NUM> (e.g., pins <NUM> tearing-out of flanges <NUM>).

The lid <NUM> may be coupled to the peripheral portion <NUM> of the frame <NUM> in manners such as described hereinbelow. In the illustrative embodiment of <FIG>, lid <NUM> is initially separably coupled to the peripheral portion <NUM> of the frame <NUM> through lid-frame connectors <NUM> that couple the surrounding walls 16a, 16b, 16c, 16d to the lid <NUM>.

Lid-frame connectors <NUM> may be generally similar in structure and operation to the frame-cassette connectors <NUM> described above. Referring to <FIG> and <FIG>, each lid-frame connector <NUM> includes a retaining structure (e.g., first retaining structure), such as a pin <NUM>, formed integrally with the peripheral portion <NUM> of frame <NUM> and extending at least partway through a retaining structure (e.g., second retaining structure), such as a flange <NUM> formed integrally with the lid <NUM>. Each pin <NUM> extends generally downwardly from a tab <NUM>, which extends generally laterally inwardly from one of the surrounding walls 16a, 16b, 16c, 16d. Pin <NUM> includes a base <NUM> (see <FIG>) disposed on tab <NUM>, a tip <NUM> on an opposite surface of flange <NUM>, and a shaft <NUM> extending from the base <NUM> to the tip <NUM> through flange <NUM>. Tip <NUM> may have a tip width <NUM> that is greater than a shaft width <NUM>. Pin <NUM> may be formed as a right circular cylinder or conical frustrum have a generally circular cross section. In this illustrative embodiment, the first retaining structure is a pin <NUM>, but it will be understood that in other embodiments the first retaining structure may take other forms, such as any shape or structure configured to extend at least partway through a corresponding second retaining structure (e.g., the flange <NUM> formed integrally with the cassette <NUM>) to attach or couple two or more components. Such first retaining structures may include, for example and without limitation, a peg, a bar, a shaft, a stem, a stick, etc., and may have any cross-sectional shape, such as generally circular, generally oval, or generally polygonal (e.g., generally square, pentagonal, hexagonal, etc.). Additionally, a first retaining structure may be generally straight or may include one or more curves, bends, or angles.

Referring to <FIG> (first position) and 4C (second position), lid-frame connectors <NUM> of this illustrative embodiment are frangible and are configured to break when lid <NUM> is moved from the first position toward the second position. In the illustrative embodiment, pin <NUM> tears out of flange <NUM>, breaking flange <NUM>, during this movement. In other embodiments with different relative sizes or material choices for pin <NUM> and flange <NUM>, pin <NUM> or tab <NUM> may break before pin <NUM> tears out of flange <NUM>. As can be seen by comparing the orientation of tabs <NUM> <FIG> and <FIG>, each tab <NUM> may be pivotably coupled to its respective surrounding wall 16a, 16b, 16c, 16d so that, during movement from the first position to the second position, tab <NUM> pivots downward, which may encourage predictable and consistent separation (e.g., breakage) of lid-frame connector <NUM> (e.g., pins <NUM> tearing-out of flanges <NUM>).

Now referring to <FIG>, <FIG>, the connections between frame <NUM> and peripheral portion <NUM> are described in more detail. Peripheral portion <NUM> is coupled to wall 14a of frame <NUM> by a pair of hinges 22a, 22b, which are optionally frangible. Peripheral portion <NUM> snap fits into the closed position (<FIG>) through the engagement of peripheral portion closure elements, which may include connectors such as latches <NUM>, <NUM> with frame closure elements, which may include connectors such as flanges <NUM>, <NUM>. Latch <NUM>, which may be in the form of a hook, is positioned on outer wall 16a of peripheral portion <NUM> and engages with flange <NUM> of wall 14a of frame <NUM> in the closed position. Latches <NUM> are positioned on wall 16c of peripheral portion <NUM> and engage (e.g., snap fit) with a flange <NUM> of wall 14c of frame <NUM> in the closed position.

Now referring to <FIG>, <FIG>, the connections between lid <NUM> and cassette <NUM> are described in more detail. Lid <NUM> snap fits into the closed position (<FIG>) through the engagement of lid closure elements, which may include connectors, such as flanges <NUM>, with cassette closure elements, which may include connectors, such as latches <NUM>. In this embodiment, lid <NUM> includes a pair of opposed flanges <NUM> arranged to snap fit with two opposed pairs of latches <NUM> in the closed position. In the closed position, with flanges <NUM> of lid <NUM> engaged with latches <NUM> of cassette <NUM>, lid <NUM> and cassette <NUM> are coupled together and move between the first position (<FIG>) and the second or staged position (<FIG>) as a single unit.

Cassette <NUM> and lid <NUM> are sized and configured to move within the interior of frame <NUM> between at least first and second positions, as shown best in <FIG> and <FIG>. Referring to <FIG>, <FIG>, and <FIG>, lid <NUM> includes a lid retention flange <NUM> on each of its four corners. Retention flanges <NUM> are configured to engage with cassette positioning elements <NUM> of frame <NUM>, which are formed as part of the interior corners of the four corners of frame <NUM>. In the illustrative embodiment, each retention flange <NUM> engages with a respective cassette positioning element <NUM>. The cassette positioning elements <NUM> are flexible and hollow such that as the retention flanges <NUM> pass by the cassette positioning elements <NUM> (e.g., downwardly), the retention flanges <NUM> deform the cassette positioning elements <NUM> and ultimately "snap" below the cassette positioning elements <NUM> as shown, for example, in <FIG>.

As shown in <FIG>, and <FIG>, each corner of frame <NUM> includes a diagonal stop <NUM> located beneath and spaced downwardly apart from the respective cassette positioning element <NUM>. When cassette <NUM> reaches the second position, stops <NUM> prevent further downward movement of retention flanges <NUM> of lid <NUM>. Thus, in the second position, retention flanges <NUM> of lid <NUM> are secured vertically between cassette positioning elements <NUM> (on the top) and stops <NUM> (on the bottom). Because lid <NUM> and cassette <NUM> are coupled together by flanges <NUM> and latches <NUM>, this retains the cassette <NUM> and lid <NUM> in the second position and ready for embedding and subsequent microtome sectioning.

As shown in <FIG>, one or more tissue samples <NUM> may be placed in cassette <NUM> that defines a recess or interior area <NUM> surrounded by at least one sidewall 12a and including a bottom wall 12b. Although a generally rectangular recess <NUM> is shown (see <FIG>), it will be appreciated that any other shape, such as any polygon (e.g., square) or any rounded shape (e.g., oval or circular) or shapes with troughs or alignment features for the tissue sample <NUM> may be used instead.

This illustrative embodiment also includes a resilient structure carried on the underside of the lid <NUM>. The resilient structure is in the form of curved, resilient fingers <NUM> for purposes of allowing flexible engagement between distal ends 42a of the resilient fingers <NUM> and the one or more tissue samples <NUM> in the cassette <NUM>. Resilient fingers <NUM> form a compliant structure that holds the tissue <NUM> in the desired orientation and position without creating an artifact impression on the tissue sample <NUM> during processing. Referring to <FIG>, in this embodiment, distal ends 42a of resilient fingers include tines 42b, which may extend generally downward when lid <NUM> is in the closed position. Tines 42b may provide additional security against undesired movement of tissue sample <NUM>.

It will be appreciated that different resilient finger <NUM> materials and configurations may be chosen based, for example, on the type of tissue to be processed and analyzed. For example, small mucosal tissue samples may be held and processed with success using some arrangements of resilient fingers <NUM>, while other types of tissue, such as fatty tissue, may be better served by another resilient finger <NUM> material or configuration. As another example, larger tissue samples may require retention structure that operates well over a large surface area. In addition, resilient fingers <NUM> may have tissue specific orientation or holding alignment features to facilitate orientation of very specific types of tissue samples. Generally, resilient fingers may be disposed on the lid in a uniform or non-uniform arrangement or orientation, may be formed (e.g., shape, thickness, or length), or may be otherwise modified as desired to facilitate accepting and retaining tissue samples of various types, sizes, or thicknesses.

Resilient fingers <NUM> allow infiltration of the solvents and chemicals used to fix, process, and stain tissue, and of embedding material used to embed the tissue while the tissue is retained by resilient fingers <NUM>. Resilient fingers <NUM> are flexible and configured to engage and retain tissue in place during processing and embedding. Further, resilient fingers <NUM> are capable of successful sectioning in the microtome after the recess or interior area of cassette is filled with liquefied embedding material which subsequently hardens. Resilient fingers <NUM> may, for example, be formed of the same material as lid <NUM>, such as a sectionable plastic.

With reference now to <FIG> and <FIG>, assembly <NUM> is shown with peripheral portion <NUM> in the closed position and where cassette <NUM> and lid <NUM> are in a first position. Once the tissue <NUM> is loaded in the interior or recess <NUM> of cassette <NUM>, peripheral portion <NUM> may be rotated to the closed position. Peripheral portion <NUM> rotates about hinges 22a, 22b, which may be frangible, to move from the open position to the closed position. If hinges 22a, 22b are frangible, such pivoting may sever hinges 22a, 22b. Peripheral portion <NUM> may rotate until latches <NUM>, <NUM> engage with flanges <NUM>, <NUM> of frame <NUM>, securely locking peripheral portion <NUM> to frame <NUM>. With peripheral portion <NUM> in the closed position, resilient fingers <NUM> bias the tissue sample <NUM> towards bottom wall 12b of cassette <NUM>.

As further shown in <FIG> and <FIG>, when lid <NUM> is closed, the resilient fingers <NUM> press against tissue sample <NUM> and deform three dimensionally around tissue sample <NUM> creating three dimensional spaces around tissue sample <NUM> and essentially immobilizing tissue sample <NUM> during the tissue processing and embedding procedures. This also ensures that the tissue sample <NUM> is held flat against bottom wall 12b of cassette <NUM> such that when microtome slices are made, progressively from bottom wall 12b towards lid <NUM>, complete and continuous sections of tissue sample <NUM> may be formed. Once all of sample <NUM> has been sliced, the next slice would contain only resilient structure <NUM> and embedding paraffin wax.

Now referring to <FIG> and <FIG>, assembly <NUM> is shown in which cassette <NUM> and lid <NUM> are in the second position. Pressing lid <NUM> downward causes lid-frame connectors <NUM> and frame-cassette connectors <NUM> to separate (as described above), allowing lid <NUM> and cassette <NUM> to move from the first position (<FIG>) towards the second position (<FIG>). Continued downward pressure on the lid <NUM> causes lid <NUM> to slide further downward inside frame <NUM>. During this downward movement, each corner of the lid <NUM> (e.g., retention flanges <NUM>) engages with its respective cassette positioning element <NUM> on the interior corner of the frame <NUM>. As the retention flanges <NUM> pass by the cassette positioning elements <NUM>, they deform the cassette positioning elements <NUM> and ultimately "snap" below the cassette positioning elements <NUM> as shown in <FIG>, which prevents upward movement of lid <NUM> and cassette <NUM>. When cassette <NUM> reaches the second position, stops <NUM> prevent further downward movement of flanges <NUM> of lid <NUM>. This retains the cassette <NUM> and lid <NUM> in the second position during the embedding and subsequent microtome sectioning process.

In the second position, tissue sample <NUM>, a portion of cassette <NUM>, and portions of resilient fingers <NUM> are staged to be sectioned in a microtome. Because cassette positioning elements <NUM> and stop <NUM> limit the travel of lid <NUM> in the second position, cassette positioning elements <NUM> and stop <NUM> assure that cassette <NUM> is staged to a predetermined depth independent of the configuration of cassette <NUM>. Staging to the predetermined depth ensures that the bottom wall 12b of the cassette <NUM> is positioned as desired with respect to the embedding mold <NUM>, such as at a predetermined vertical spacing (see <FIG>). This facilitates the use of automated microtomes in the processes described below because the thickness of the embedding material that must be removed before reaching the tissue sample <NUM> held against the bottom wall 12b will be substantially the same for all cassettes.

Because there are millions of procedures completed each year utilizing assemblies like these, embodiments of the present invention are designed for high production volumes and, consequently, are directed towards use in automated histopathology processes. One such process is automated embedding. An exemplary automated embedding machine uses a motorized staging device <NUM> that pushes the cassette through the frame into the embedding mold <NUM> as shown in <FIG> and <FIG>. A staging device <NUM> may incorporate spring-loaded cylindrical fingers or feet which push the lid <NUM> and cassette <NUM> through frame <NUM>.

In use, one or more tissue samples <NUM> are placed within the interior space or recess and, specifically, on bottom wall 12b of cassette <NUM> as shown in <FIG>. Tissue sample <NUM> is sized and oriented in cassette <NUM> according to the required section plane desired by the pathologist for each tissue sample <NUM>. Peripheral portion <NUM> is then closed and snapped into place such that resilient fingers <NUM> bear against and trap tissue sample <NUM> against bottom wall 12b in the desired orientation as shown in <FIG>. Resilient fingers <NUM> may deform three dimensionally to accommodate various sizes and shapes of tissue samples <NUM>. The force of resilient fingers <NUM> against tissue sample <NUM> should be enough to immobilize tissue sample <NUM> and trap it against bottom wall 12b, but not enough to induce artifacts in tissue sample <NUM>. At this point, assembly <NUM> with the trapped tissue sample <NUM> may be subjected to a conventional tissue processing operation that uses vacuum, heat and chemicals to remove the interstitial fluids within the tissue and replace those fluids with a hardenable material, such as molten paraffin. As mentioned above, during these processing steps, the resilient fingers <NUM> and bottom wall 12b allow the fluids to reach and fully infiltrate into tissue sample <NUM>.

The illustrated configuration of cassette <NUM>, frame <NUM>, and lid <NUM>, including resilient fingers <NUM>, is an improvement over assemblies that require a complex lid adjustment procedure whereby the user must choose from a limited number of specific engagement distances between the lid and the cassette to ensure that the tissue sample <NUM> is properly immobilized against the bottom wall 12b of the cassette. The specific engagement distances were determined by preset tabs in the interior of the cassette basket that engaged and retained the lid. By utilizing the illustrative embodiment, and particularly the resilient fingers <NUM> (or other similar tissue biasing structures disclosed herein), the complex adjustment procedure for the lid is eliminated. Accordingly, in some exemplary embodiments, lid closure and proper immobilization of the tissue sample (without excessive deformation) may be accomplished by a simple, "one-snap" procedure in which the lid is closed and the resilient fingers <NUM> (or other similar biasing structures) properly bias the tissue sample <NUM> against the bottom wall 12b of the cassette <NUM>, regardless of the thickness of the tissue sample. It will be appreciated that other configurations and designs may be used to achieve similar purposes.

After the tissue processing is complete, cassette <NUM> and frame <NUM> are then placed into a suitable mold <NUM> and embedded in paraffin. Cassette <NUM> and/or frame <NUM> may include machine-readable indicia allowing a machine to determine the type and size cassette <NUM> being used and to make an appropriate decision as to which mold to place the cassette <NUM> in for embedding. The entire assembly <NUM> including the exposed portion of cassette <NUM> is embedded within a hardened block of paraffin wax. The mold <NUM> may generally follow the contour of the bottom 12b of cassette <NUM>, although the portion of the mold surrounding cassette <NUM> is preferably square as opposed to round. This assists with the subsequent production of ribbon slices. The frame <NUM> is then used as a fixture for mounting the embedded assembly <NUM> in a microtome. The necessary number of slices are taken off of the exposed underside until enough sections or slices are taken and appropriately mounted on a microscope slide, stained and cover slipped.

Another method (not shown) of loading tissue sample <NUM> in assembly <NUM> is possible. First, peripheral portion <NUM> is detached from frame <NUM>, which is set aside. Tissue sample <NUM> is placed onto resilient fingers <NUM>, and then frame <NUM> is installed on top of lid <NUM>. When frame <NUM> is installed on top of peripheral portion <NUM>, latches <NUM>, <NUM> of peripheral portion <NUM> engage with flanges <NUM>, <NUM>, respectively, of frame <NUM>. In this manner, peripheral portion <NUM> is secured to frame <NUM>. Assembly <NUM> may then be positioned in its usual upright position while resilient lid <NUM> remains coupled to frame <NUM> and resilient fingers <NUM> secure tissue sample <NUM> to bottom wall 12b of cassette <NUM>.

Generally, cassette <NUM> (and, in some embodiments, lid <NUM>) may be formed of a relatively less rigid material and frame <NUM> (and, in some embodiments, lid <NUM>) may be formed of a relatively more rigid material. Cassette <NUM> may be formed from a sectionable plastic, such as perfluoroalkoxyethylene (PFA), or polyethylene (PE)-based. The material forming cassette <NUM> may be at least translucent so as to be non-distracting during tissue analysis. Frame <NUM>, including peripheral portion <NUM>, may be formed from a more rigid, less costly plastic, such as acetal. Acetal is far easier to mold in large quantities or in multi-cavity injection molds. As will be appreciated from <FIG>, cassette <NUM> may be molded separately from the frame <NUM> and then inserted into the frame <NUM>. Similarly, lid <NUM> may be molded separately from the peripheral portion <NUM> and then inserted into the peripheral portion <NUM>. Further, when cassette <NUM> and frame <NUM> are made of materials with significantly different melting temperatures, they can be insert molded or co-molded, such as using the two-shot technique described below in connection with <FIG>. In some illustrative embodiments, the cassette <NUM>, lid <NUM>, and frame <NUM> may be combined into a single piece prior to the customer receiving them, so the assembly arrives as a single piece ready to load with tissue. This is advantageous over prior assemblies where the user was required to assemble the components before loading the tissue.

<FIG> shows the pin connector <NUM>, which is structurally similar to connector <NUM> but in a generally inverse configuration.

<FIG> illustrate an example assembly process, specifically pertaining to frame-cassette connectors <NUM>. <FIG> shows the frame <NUM> and the components integrally formed therewith, including tab <NUM> and pin <NUM>. Notably, pin <NUM> does not yet include its wide tip <NUM> (<FIG> and <FIG>). Pin <NUM> may be generally frustoconical, which may facilitate release of the mold used to form frame <NUM> and associated components. <FIG> shows the cassette and the components integrally formed therewith, including flange <NUM> positioned with respect to pin <NUM> such that shaft <NUM> of pin extends through flange <NUM>. This may be accomplished by assembling a separately molded frame <NUM> and cassette <NUM>, or it may be accomplished by sequentially molding the frame <NUM> and cassette <NUM> in place. <FIG> also shows tool <NUM> approaching pin <NUM>. <FIG> shows pin <NUM> with the distal portion of its shaft <NUM> formed into a relatively wider tip <NUM> by operation of tool <NUM>. This deformation of pin <NUM> to form tip <NUM> secures flange <NUM> of cassette <NUM> to pin <NUM> of frame <NUM>. In some exemplary processes, the tip <NUM> may be formed by the tool <NUM> when the pin <NUM> is at a temperature above room temperature but below its melting temperature so that the distal portion of the shaft <NUM> may be readily plastically deformed by the tool. <FIG> shows the completed frame-cassette connectors <NUM> as previously described. A generally similar, corresponding process may be used to assemble lid-frame connectors <NUM>.

<FIG>, <FIG>, and <FIG> illustrate alternative example retaining structures comprising pin/flange connectors and associated methods of assembly. The examples described above with respect to <FIG> or any of the alternative examples described below with respect to <FIG>, <FIG>, and <FIG> may be utilized in connection with various embodiments according to the present disclosure. <FIG> are cross sectional views of an alternative pin/flange connector <NUM> showing steps of a two-shot, co-molding process. In <FIG>, a pin <NUM> is formed integrally with a first component <NUM>, such as by injection molding. This operation may be referred to as a first molding operation or a first shot. In the context of assembly <NUM> illustrated in <FIG>, first component <NUM> may be frame <NUM>. In <FIG>, a mold/tool <NUM> is shown approaching the first component <NUM>. Referring to <FIG>, the mold/tool <NUM> engages the first component <NUM> to deform the pin <NUM> to form a wider, mushroom head shaped tip <NUM>. In some exemplary processes, the tip <NUM> may be formed by the mold/tool <NUM> when the pin <NUM> is at a temperature above room temperature but below its melting temperature so that the distal portion of the pin may be readily plastically deformed by the mold/tool. Additionally, the mold/tool <NUM> engages the first component <NUM> to at least partially define one or more cavities <NUM> for molding a second material. As shown in <FIG>, cavity <NUM> is filled in a second molding operation or second shot to form a flange <NUM>, formed integrally with a second component <NUM>, disposed about pin <NUM>. Generally, because the flange <NUM> extends within the recess or undercut beneath the tip and surrounding the pin <NUM>, the flange is secured to the pin until the connector <NUM> is separated (e.g., broken) in the staging operation. In the context of assembly <NUM> illustrated in <FIG>, second component <NUM> may be cassette <NUM>. Such a two-shot molding process may be advantageous compared to some other potential assembly or molding processes because it may involve fewer handling and assembly steps, for example. In an exemplary two-shot processes, the first component <NUM> may be formed in a mold. Without removing the first component <NUM> from the mold, the mold may reconfigured (e.g., rotated <NUM> degrees) to receive mold/tool <NUM>. Then, the second component <NUM> may be molded. Finally, the first component <NUM> and the second component <NUM>, now connected, may be removed. Accordingly, this exemplary two-shot process may not require transferring the first component from a first mold to a second mold or assembly of separately molded components.

In other exemplary processes, first component <NUM> may be formed and then placed into a second mold Then, second component <NUM> may be formed, such as by injection molding, directly on first component <NUM>, such as by a co-molding or insert molding process. Generally, first component <NUM> may be shaped such that any cavities generally narrow with increasing depth to facilitate mold release. Similarly, pin <NUM> may be generally frustoconical, with the narrower end facing out, to facilitate mold release.

<FIG> are cross sectional views of an alternative pin/flange connector <NUM> showing steps of an assembly process. In <FIG>, a first component <NUM> includes a recess <NUM> into which a pin <NUM> is installed and secured. For example, the pin <NUM> may be secured in the recess <NUM> using an adhesive. First component <NUM> may be formed of a first material, and pin <NUM> may be formed of a second material. Pin <NUM> may be generally frustoconical and includes a recess <NUM> at its distal end. In <FIG>, a tool <NUM> is forming a tip <NUM> on pin <NUM>. Tool <NUM> includes a central projection <NUM> arranged to engage recess <NUM> of pin <NUM>. In <FIG>, a second component <NUM> (e.g., comprising a flange) has been molded in the recess <NUM> around pin <NUM>, such as by injection molding. Second component <NUM> may be formed of a third material. Accordingly, connector <NUM> couples first component <NUM> and second component <NUM>. More specifically, because the flange of the second component <NUM> extends within the recess or undercut beneath the tip <NUM> and surrounding the pin <NUM>, the second component is secured to the first component <NUM> until the connector <NUM> is separated (e.g., broken) in the staging operation.

<FIG> are cross sectional views of an alternative pin/flange connector <NUM> showing steps of an assembly process. Pin connector <NUM> may be generally similar to pin connector <NUM>, except that pin <NUM> may be formed integrally with first component <NUM>. In <FIG>, first component <NUM> includes a recess <NUM> within which a pin <NUM> is integrally formed. First component <NUM> and pin <NUM> may be formed of a first material. Pin <NUM> may be generally frustoconical. In <FIG>, a tool <NUM> is forming a tip <NUM> on pin <NUM>. Alternatively, in some exemplary embodiments having appropriate geometries, the tip <NUM> may be molded during the initial molding of the first component <NUM> so that the tool <NUM> and separate tip-forming step may be omitted. In <FIG>, a second component <NUM> (e.g., comprising a flange) has been molded in the recess <NUM> around pin <NUM>, such as by injection molding in a second mold. Second component <NUM> may be formed of a second material. Accordingly, connector <NUM> couples first component <NUM> and second component <NUM>. More specifically, because the flange of the second component <NUM> extends within the recess or undercut beneath the tip <NUM> and surrounding the pin <NUM>, the second component is secured to the first component <NUM> until the connector <NUM> is separated (e.g., broken) in the staging operation.

Although several exemplary processes for forming and assembling certain exemplary frame-cassette connectors, lid-frame connectors, and other components are described herein, it is to be understood that various devices including such connectors and methods of using the devices may be within the scope of this disclosure, regardless of whether the devices are produced using the processes described above, conventional processes, or any combination thereof.

<FIG>, <FIG>, and <FIG> depict another illustrative embodiment of an assembly <NUM> that is generally similar to assembly <NUM> shown and described with respect to <FIG>, <FIG>, <FIG>, <FIG>, and <FIG>. Like reference numerals refer to like structure shown and described above. Unless specifically indicated, the description of the structure and function or methodology of corresponding components with respect to assembly <NUM> generally applies to assembly <NUM>. Therefore, repeated explanation of previously described structure and function or methodology is not necessary. In this embodiment, the resilient fingers <NUM> of assembly <NUM> have been replaced by a generally rectangular platen <NUM> and biasing members <NUM>. Further, assembly <NUM> includes a different arrangement of lid closure elements and cassette closure elements.

The assembly <NUM> includes a tissue sample cassette <NUM> including a recess or interior area <NUM> surrounded by at least one sidewall 112a and including a bottom wall 112b. Cassette <NUM> is carried within and separably coupled to a frame <NUM>, which includes a peripheral portion <NUM>. A lid <NUM> is separably coupled to the peripheral portion <NUM>. Peripheral portion <NUM> generally includes an interior defined between surrounding (peripheral) walls 116a, 116b, 116c, 116d, and lid <NUM> is sized and configured to fit in the interior and is separably coupled to at least one of the surrounding walls 116a, 116b, 116c, 116d. The frame <NUM> generally includes an interior defined between surrounding outer walls 114a, 114b, 114c, 114d and a bottom edge 114e, and the cassette <NUM> is sized and configured to move within the interior between at least first and second positions, as generally described above in connection with assembly <NUM> and for the same purposes. The first position is shown in <FIG>, while the second, "staged" position is shown in <FIG> in which the lower portion of the cassette <NUM> is exposed below the bottom edge 114e of the frame <NUM> for allowing cassette <NUM> and embedded tissue sample to be sectioned in a microtome while the frame <NUM> is held in the microtome chuck.

The connection of the tissue cassette <NUM> to the frame <NUM> may be accomplished in many different manners, such as any of the manners described above. In the illustrative embodiment of <FIG>, cassette <NUM> is initially separably coupled to frame <NUM> through frame-cassette connectors <NUM> that couple the surrounding walls 114a, 114b, 114c, 114d to the cassette <NUM>. Frame-cassette connectors <NUM> are similar in construction and operation to frame-cassette connectors <NUM> described above in connection with assembly <NUM>. In this illustrative embodiment, frame-cassette connectors <NUM> are frangible.

The connection of the lid <NUM> to the peripheral portion <NUM> of the frame <NUM> may be accomplished in many different manners, such as any of the manners described above. In the illustrative embodiment of <FIG>, lid <NUM> is initially separably coupled to the peripheral portion <NUM> of the frame <NUM> through lid-frame connectors <NUM> that couple the surrounding walls 116a, 116b, 116c, 116d to the lid <NUM>. Lid-frame connectors <NUM> are similar in construction and operation to lid-frame connectors <NUM> described above in connection with assembly <NUM>. In this illustrative embodiment, lid-frame connectors <NUM> are frangible.

Now referring to <FIG> and <FIG>, the connections between frame <NUM> and peripheral portion <NUM> are shown in more detail. Peripheral portion <NUM> is coupled to wall 114a of frame <NUM> by a pair of hinges 122a, 122b, which are optionally frangible. Peripheral portion <NUM> snap fits into the closed position (<FIG>) through the engagement of peripheral portion closure elements, such as latches <NUM>, <NUM> with frame closure elements, such as flanges <NUM>, <NUM>. Latch <NUM> is positioned on outer wall 116a of peripheral portion <NUM> and engages with flange <NUM> in wall 114a of frame <NUM> in the closed position. Latches <NUM> are positioned on wall 116c of peripheral portion <NUM> and engage with flange <NUM> of wall 114c of frame <NUM> in the closed position.

Referring to <FIG>, <FIG>, and <FIG>, the connections between lid <NUM> and cassette <NUM> are shown in more detail. Lid <NUM> snap fits into the closed position (<FIG>) through the engagement of lid closure elements, which may include connectors, such as latches <NUM>, with cassette closure elements, which may include connectors, such as flanges <NUM>. In this embodiment, each latch <NUM> is disposed on a respective extending arm <NUM>. The arms <NUM> extend generally downwardly from the lid <NUM> when the lid <NUM> is in the closed position. A corresponding pair of arms <NUM> and latches <NUM> is disposed on each lateral side of lid <NUM>, with the arms <NUM> and latches <NUM> in each pair disposed on the lid in a spaced-apart, opposed arrangement such that latches <NUM> face each other. Each flange <NUM> of cassette <NUM> is oriented generally laterally and is arranged to engage both latches <NUM> of a corresponding pair of arms <NUM>. In the closed position, with latches <NUM> of lid <NUM> engaged with flanges <NUM> of cassette <NUM>, lid <NUM> and cassette <NUM> are coupled together and move between the first position (<FIG>) and the second or staged position (<FIG>) as a single unit. Generally, the lid closure elements serve to secure the lid to the cassette and to prevent the lid and the cassette from separating after the lid has been closed onto the cassette, such as during the various processing operations. In some exemplary embodiments including lid-mounted components arranged to bias the tissue sample against the bottom wall of the cassette, the lid closure elements may be configured to withstand the corresponding reaction force that may tend to separate the lid from the cassette.

Cassette <NUM> and lid <NUM> are sized and configured to move within the interior of frame <NUM> between at least first and second positions, as shown best in <FIG> and <FIG> in a manner similar to that described above with respect to assembly <NUM>. Lid <NUM> includes a lid retention flange <NUM> on each of its four corners. Retention flanges <NUM> are configured to engage with cassette positioning elements <NUM> of frame <NUM>, which are formed as part of the interior corners of the four corners of frame <NUM>. In the illustrative embodiment, each retention flange <NUM> engages with a respective cassette positioning element <NUM>. The cassette positioning elements <NUM> are flexible and hollow such that as the retention flanges <NUM> pass by the cassette positioning elements <NUM> (e.g., downwardly), the retention flanges <NUM> deform the cassette positioning elements <NUM> and ultimately "snap" below the cassette positioning elements <NUM> as shown, for example, in <FIG>.

As shown in <FIG> and <FIG>, each corner of frame <NUM> includes a diagonal stop <NUM> located beneath and spaced downwardly apart from the respective cassette positioning element <NUM>. When cassette <NUM> reaches the second position, stops <NUM> prevent further downward movement of retention flanges <NUM> of lid <NUM>. Thus, in the second position, retention flanges <NUM> of lid <NUM> are secured vertically between cassette positioning elements <NUM> (on the top) and stops <NUM> (on the bottom). Because lid <NUM> and cassette <NUM> are coupled together by latches <NUM> and flanges <NUM>, this retains the cassette <NUM> and lid <NUM> in the second position, and ready for embedding and subsequent microtome sectioning, as described above.

Referring to <FIG>, <FIG>, and <FIG>, instead of the resilient fingers <NUM> of assembly <NUM> described above, the lid <NUM> of this embodiment includes a resilient structure comprising a platen <NUM> configured to be received within generally rectangular recess <NUM> of cassette <NUM>. Platen <NUM> is generally rectangular and is coupled to a peripheral portion <NUM> of the lid <NUM> by a plurality of biasing members <NUM>. Biasing members <NUM> are arranged to bias the platen <NUM> towards bottom wall 112b of cassette <NUM> when the lid <NUM> is in the closed configuration. In this embodiment, the biasing members <NUM> are disposed in a generally perpendicular arrangement between platen <NUM> and the peripheral portion <NUM> of the lid <NUM>.

Generally, biasing members <NUM> are elastically deformable to allow flexible engagement between platen <NUM> and the one or more tissue samples in the recess <NUM> of cassette <NUM>. Platen <NUM> and biasing members <NUM> form a compliant structure that holds the tissue in the desired orientation without creating an artifact impression on the tissue sample during processing. Although a generally rectangular recess <NUM> is shown, it will be appreciated that any other shape, such as any polygon (e.g., square) or any rounded shape (e.g., oval or circular) or shapes with troughs or alignment features for the tissue sample may be used instead.

Platen <NUM> allows infiltration of the solvents and chemicals used to fix, process, and stain tissue, and of embedding material used to embed the tissue while the tissue is retained by platen <NUM>. Platen <NUM> is flexible and configured to engage and retain tissue in place during processing and embedding. Further, platen <NUM> is capable of successful sectioning in the microtome after the recess <NUM> or interior area of cassette is filled with liquefied embedding material which subsequently hardens. Platen <NUM> may, for example, be formed of the same material as lid <NUM>, such as a sectionable plastic.

Referring to <FIG>, in this embodiment, the tissue-contacting side of platen <NUM> includes tines 142b, which may extend generally downward when lid <NUM> is in the closed position. Tines 142b may provide additional security against undesired movement of the tissue samples.

Generally, assembly <NUM> is loaded with tissue, moved from the open position to the closed position (including breaking frangible lid-frame connectors <NUM> and frame-cassette connectors <NUM>), staged, and otherwise used in a manner similar to assembly <NUM> described above. In use, one or more tissue samples are placed within the interior space or recess <NUM> and, specifically, on bottom wall 112b of cassette <NUM>. The tissue sample is sized and oriented in cassette <NUM> according to the required section plane desired by the pathologist. Peripheral portion <NUM> is then closed and snapped into place such that platen <NUM> bears against and traps the tissue sample against bottom wall 112b in the desired orientation. Biasing members <NUM> deform to allow platen <NUM> to accommodate various sizes and shapes of tissue samples. The force of platen <NUM> against the tissue sample should be enough to immobilize the tissue sample but not enough to induce artifacts in the tissue sample. At this point, assembly <NUM> with the trapped tissue sample may be subjected to a conventional tissue processing operation that uses vacuum, heat and chemicals to remove the interstitial fluids within the tissue and replace those fluids with a hardenable material, such as molten paraffin. As mentioned above, during these processing steps, the platen <NUM> and bottom wall 112b allow the fluids to reach and fully infiltrate into tissue sample. In addition, platen <NUM> traps the tissue sample flat against bottom wall 112b without leaving artifacts or markings on the tissue that might interfere with subsequent analysis under a microscope. It will be appreciated that different biasing member <NUM> and platen <NUM> materials and configurations may be chosen based, for example, on the type of tissue to be processed and analyzed. For example, small mucosal tissue samples may be held and processed with success using some arrangements, while other types of tissue, such as fatty tissue, may be better served by another material or configuration. For example, the thickness, shape, and number of biasing members may be selected to provide a desired immobilizing force on the tissue samples.

After the tissue processing is complete, cassette <NUM> and frame <NUM> are then placed into a suitable mold and embedded in paraffin. Cassette <NUM> and/or frame <NUM> may include machine-readable indicia allowing a machine to determine the type and size cassette <NUM> being used and to make an appropriate decision as to which mold to place the cassette <NUM> in for embedding generally in the manner described above with reference to assembly <NUM>.

<FIG>, <FIG>, <FIG>, <FIG>, and <FIG> depict another illustrative embodiment of an assembly <NUM> that is similar to assembly <NUM> shown and described with respect to <FIG>, <FIG>, and <FIG>, as well as assembly <NUM>. Like reference numerals in <FIG>, <FIG>, <FIG>, <FIG>, and <FIG> refer to like structure shown and described above. Unless specifically indicated, the description of the structure and function or methodology of corresponding components with respect to assembly <NUM> and assembly <NUM> generally applies to assembly <NUM>. Therefore, repeated explanation of previously described structure and function or methodology is not necessary. In this embodiment, the generally rectangular platen <NUM> of assembly <NUM> has been replaced by generally circular platen <NUM>, and the generally perpendicular biasing members <NUM> of assembly <NUM> have been replaced by generally helical biasing members <NUM>. Further, assembly <NUM> includes a different arrangement of lid closure elements and cassette closure elements.

The assembly <NUM> includes a tissue sample cassette <NUM> including a recess or interior area <NUM> surrounded by at least one sidewall 212a and including a bottom wall 212b. Cassette <NUM> is carried within and separably coupled to a frame <NUM>, which includes a peripheral portion <NUM>. A lid <NUM> is separably coupled to the peripheral portion <NUM>. Peripheral portion <NUM> generally includes an interior defined between surrounding (peripheral) walls 216a, 216b, 216c, 216d, and lid <NUM> is sized and configured to fit in the interior and is separably coupled to at least one of the surrounding walls 216a, 216b, 216c, 216d. The frame <NUM> generally includes an interior defined between surrounding outer walls 214a, 214b, 214c, 214d and a bottom edge 214e, and the cassette <NUM> is sized and configured to move within the interior between at least first and second positions, as generally described above in connection with assembly <NUM> and for the same purposes. The first position is shown in <FIG>, while the second, "staged" position is shown in <FIG> in which the lower portion of the cassette <NUM> is exposed below the bottom edge 214e of the frame <NUM> for allowing cassette <NUM> and embedded tissue sample to be sectioned in a microtome while the frame <NUM> is held in the microtome chuck.

The connection of the tissue cassette <NUM> to the frame <NUM> may be accomplished in many different manners, such as any of the manners described above. In the illustrative embodiment of <FIG>, cassette <NUM> is initially separably coupled to frame <NUM> through frame-cassette connectors <NUM> that couple the surrounding walls 214a, 214b, 214c, 214d to the cassette <NUM>. Frame-cassette connectors <NUM> are similar in construction and operation to frame-cassette connectors <NUM> described above in connection with assembly <NUM>. In this illustrative embodiment, frame-cassette connectors <NUM> are frangible.

The connection of the lid <NUM> to the peripheral portion <NUM> of the frame <NUM> may be accomplished in many different manners, such as any of the manners described above. In the illustrative embodiment of <FIG>, lid <NUM> is initially separably coupled to the peripheral portion <NUM> of the frame <NUM> through lid-frame connectors <NUM> that couple the surrounding walls 216a, 216b, 216c, 216d to the lid <NUM>. Lid-frame connectors <NUM> are similar in construction and operation to lid-frame connectors <NUM> described above in connection with assembly <NUM>. In this illustrative embodiment, lid-frame connectors <NUM> are frangible.

Now referring to <FIG>, <FIG>, and <FIG>, the connections between frame <NUM> and peripheral portion <NUM> are shown in more detail. Peripheral portion <NUM> is coupled to wall 214a of frame <NUM> by a pair of hinges 222a, 222b, which are optionally frangible. Peripheral portion <NUM> snap fits into the closed position (<FIG>) through the engagement of peripheral portion closure elements, such as latches <NUM>, <NUM> with frame closure elements, such as flanges <NUM>, <NUM>. Latch <NUM> is positioned on outer wall 216a of peripheral portion <NUM> and engages with flange <NUM> in wall 214a of frame <NUM> in the closed position. Latches <NUM> are positioned on wall 216c of peripheral portion <NUM> and engage with a flange <NUM> of wall 214c of frame <NUM> in the closed position.

Referring to <FIG>, <FIG>, and <FIG>, the connections between lid <NUM> and cassette <NUM> are shown in more detail. Lid <NUM> snap fits into the closed position (<FIG>) through the engagement of lid closure elements, which may include connectors, such as latches <NUM>, with cassette closure elements, which may include connectors, such as flanges <NUM>. In this embodiment, each of four latches <NUM> is disposed on a respective extending arm <NUM>. The arms <NUM> extend generally downwardly from the lid <NUM> when the lid <NUM> is in the closed position. The arms <NUM> are disposed in a spaced-apart arrangement generally surrounding platen <NUM>, and latches <NUM> face generally laterally outwards from their respective arms. Each of the four flanges <NUM> of cassette <NUM> is oriented generally laterally and is arranged to engage one latch <NUM>. In the closed position, with latches <NUM> of lid <NUM> engaged with flanges <NUM> of cassette <NUM>, lid <NUM> and cassette <NUM> are coupled together and move between the first position (<FIG>) and the second or staged position (<FIG>) as a single unit.

As best shown in <FIG>, each corner of frame <NUM> includes a diagonal stop <NUM> located beneath and spaced downwardly apart from the respective cassette positioning element <NUM>. When cassette <NUM> reaches the second position, stops <NUM> prevent further downward movement of retention flanges <NUM> of lid <NUM>. Thus, in the second position, retention flanges <NUM> of lid <NUM> are secured vertically between cassette positioning elements <NUM> (on the top) and stops <NUM> (on the bottom). Because lid <NUM> and cassette <NUM> are coupled together by latches <NUM> and flanges <NUM>, this retains the cassette <NUM> and lid <NUM> in the second position, and ready for embedding and subsequent microtome sectioning.

Referring to <FIG>, <FIG>, <FIG>, <FIG>, and <FIG>, instead of generally rectangular platen <NUM> of assembly <NUM> described above, the lid <NUM> of this embodiment includes a resilient structure comprising a generally circular platen <NUM> configured to be received within generally circular recess <NUM> of cassette <NUM>. Platen <NUM> is coupled to a peripheral portion <NUM> of the lid <NUM> by a plurality of biasing members <NUM>. Biasing members <NUM> are arranged to bias the platen <NUM> towards bottom wall 212b of cassette <NUM> when the lid <NUM> is in the closed configuration. In this embodiment, the biasing members <NUM> are disposed in an angled arrangement, and, more specifically, a generally helical arrangement between platen <NUM> and the peripheral portion <NUM> of the lid <NUM>.

Generally, biasing members <NUM> are elastically deformable to allow flexible engagement between platen <NUM> and the one or more tissue samples in the recess <NUM> of cassette <NUM>. Platen <NUM> and biasing members <NUM> form a compliant structure that holds the tissue in the desired orientation without creating an artifact impression on the tissue sample during processing. Although a generally circular recess <NUM> is shown, it will be appreciated that any other shape, such as any polygon (e.g., square or rectangle) or any rounded shape (e.g., oval) or shapes with troughs or alignment features for the tissue sample, may be used instead.

Referring to <FIG>, in this embodiment, the tissue-contacting side of platen <NUM> includes tines 242b, which may extend generally downward when lid <NUM> is in the closed position. Tines 242b may provide additional security against undesired movement of the tissue sample.

Generally, assembly <NUM> is loaded with tissue, moved from the open position to the closed position (including breaking frangible lid-frame connectors <NUM> and frame-cassette connectors <NUM>), staged, and otherwise used in a manner similar to assembly <NUM> and assembly <NUM> described above. In use, one or more tissue samples are placed within the interior space or recess <NUM> and, specifically, on bottom wall 212b of cassette <NUM>. The tissue sample is sized and oriented in cassette <NUM> according to the required section plane desired by the pathologist. Peripheral portion <NUM> is then closed and snapped into place such that platen <NUM> bears against and traps the tissue sample against bottom wall 212b in the desired orientation. Biasing members <NUM> may deform to allow platen <NUM> to accommodate various sizes and shapes of tissue samples. The force of platen <NUM> against the tissue sample should be enough to immobilize the tissue sample but not enough to induce artifacts in the tissue sample. At this point, assembly <NUM> with the trapped tissue sample may be subjected to a conventional tissue processing operation that uses vacuum, heat and chemicals to remove the interstitial fluids within the tissue and replace those fluids with a hardenable material, such as molten paraffin. As mentioned above, during these processing steps, the platen <NUM> and bottom wall 212b allow the fluids to reach and fully infiltrate into tissue sample. In addition, platen <NUM> traps the tissue sample flat against bottom wall 212b without leaving artifacts or markings on the tissue that might interfere with subsequent analysis under a microscope. It will be appreciated that different biasing member <NUM> and platen <NUM> materials and configurations may be chosen based, for example, on the type of tissue to be processed and analyzed. For example, small mucosal tissue samples may be held and processed with success using some arrangements, while other types of tissue, such as fatty tissue, may be better served by another material or configuration. For example, the thickness, shape, and number of biasing members <NUM> may be selected to provide a desired immobilizing force on the tissue samples.

After the tissue processing is complete, cassette <NUM> and frame <NUM> are then placed into a suitable mold and embedded in paraffin. Cassette <NUM> and/or frame <NUM> may include machine-readable indicia allowing a machine to determine the type and size cassette <NUM> being used and to make an appropriate decision as to which mold to place the cassette <NUM> in for embedding generally in the manner described above with reference to assembly <NUM> and assembly <NUM>.

<FIG>, <FIG>, and <FIG> depict another illustrative embodiment of an assembly <NUM> that is generally similar to assembly <NUM> shown and described with respect to <FIG>, <FIG>, <FIG>, <FIG>, and <FIG>, as well as other illustrative embodiments described herein. Like reference numerals refer to like structure shown and described above. Unless specifically indicated, the description of the structure and function or methodology of corresponding components with respect to assembly <NUM> and other illustrative embodiments generally applies to assembly <NUM>. Therefore, repeated explanation of previously described structure and function or methodology is not necessary.

In assembly <NUM>, the lid-frame connectors <NUM> and frame-cassette connectors <NUM> of assembly <NUM> have been replaced by lid-frame connectors <NUM> and frame-cassette connectors <NUM>, respectively, which generally comprise inverted versions of lid-frame connectors <NUM> and frame-cassette connectors <NUM>. Also, assembly <NUM> includes stress risers <NUM> in flanges <NUM>. Further, assembly <NUM> includes peripheral portion closure elements (e.g., latches <NUM> and flanges <NUM>) arranged to couple lateral side surrounding (peripheral) walls 316b, 316d to lateral side surrounding outer walls 314b, 314d, respectively. Any one or more of these features may be optionally included in any other exemplary embodiment.

The assembly <NUM> includes a tissue sample cassette <NUM> generally similar to sample cassette <NUM>. Cassette <NUM> is carried within and separably coupled to a frame <NUM>, which includes a peripheral portion <NUM> and which is generally similar to frame <NUM> and peripheral portion <NUM>. A lid <NUM> (generally similar to lid <NUM>) is separably coupled to the peripheral portion <NUM>. Peripheral portion <NUM> generally includes an interior defined between surrounding (peripheral) walls 316a, 316b, 316c, 316d, and lid <NUM> is sized and configured to fit in the interior and is separably coupled to at least one of the surrounding walls 316a, 316b, 316c, 316d. The frame <NUM> generally includes an interior defined between surrounding outer walls 314a, 314b, 314c, 314d, and the cassette <NUM> is sized and configured to move within the interior between at least first and second positions, as generally described above in connection with assembly <NUM> and for the same purposes.

The connection of the tissue cassette <NUM> to the frame <NUM> may be accomplished in many different manners, such as any of the manners described above. In the illustrative embodiment of <FIG>, cassette <NUM> is initially separably coupled to frame <NUM> through frame-cassette connectors <NUM> that couple the surrounding walls 314a, 314b, 314c, 314d to the cassette <NUM>. Frame-cassette connectors <NUM> are similar in construction and operation to frame-cassette connectors <NUM> described above in connection with assembly <NUM>, except that their orientation is inverted.

Specifically, each frame-cassette connector <NUM> includes a retaining structure (e.g., first retaining structure), such as a pin <NUM>, formed integrally with the frame <NUM> and extending at least partway through a retaining structure (e.g., second retaining structure), such as a flange <NUM> formed integrally with the cassette <NUM>. Each pin <NUM> extends generally downwardly (as compared to generally upwardly in assembly <NUM>) from a tab <NUM>, which extends generally laterally inwardly from one of the outer walls 314a, 314b, 314c, 314d. Generally, because the tip of the pin <NUM> and the tab <NUM> are wider than the shaft extending therebetween, and because the flange <NUM> extends within the recessed or undercut area between the tip and the tab, the flange is retained on the pin by the tip and the tab. Accordingly, until the frame-cassette connector <NUM> is separated (e.g., broken) during the staging operation, the flange <NUM> is secured to the pin <NUM>.

The frame-cassette connectors <NUM> of this illustrative embodiment are frangible and are configured to break when cassette <NUM> is moved from the first position toward the second position as described above in connection with assembly <NUM>. In this illustrative embodiment, pin <NUM> tears out of flange <NUM>, breaking flange <NUM>, during this movement. Each tab <NUM> may be pivotably coupled to its respective outer wall 314a, 314b, 314c, 314d so that, during movement from the first position to the second position, tab <NUM> pivots downward, which may encourage predictable and consistent separation (e.g., breakage) of frame-cassette connector <NUM> (e.g., pins <NUM> tearing-out of flanges <NUM>).

The connection of the lid <NUM> to the peripheral portion <NUM> of the frame <NUM> may be accomplished in many different manners, such as any of the manners described above. In the illustrative embodiment of <FIG>, lid <NUM> is initially separably coupled to the peripheral portion <NUM> of the frame <NUM> through lid-frame connectors <NUM> that couple the surrounding walls 316a, 316b, 316c, 316d to the lid <NUM>. Lid-frame connectors <NUM> are similar in construction and operation to lid-frame connectors <NUM> described above in connection with assembly <NUM>, except that their orientation is inverted.

Specifically, lid-frame connectors <NUM> may be generally similar in structure and operation to the frame-cassette connectors <NUM> described above. Each lid-frame connector <NUM> includes a retaining structure (e.g., first retaining structure), such as a pin <NUM>, formed integrally with the peripheral portion <NUM> of frame <NUM> and extending at least partway through a retaining structure (e.g., second retaining structure), such as a flange <NUM> formed integrally with the lid <NUM>. In the open position, each pin <NUM> extends generally downwardly (as compared to generally upwardly in assembly <NUM>) from a tab <NUM>, which extends generally laterally inwardly from one of the surrounding walls 316a, 316b, 316c, 316d. Similarly, in the closed configuration (e.g., similar to <FIG>), the pins <NUM> extend generally upwardly from the tabs <NUM>. Pin <NUM> includes a base disposed on tab <NUM>, a tip on an opposite surface of flange <NUM>, and a shaft extending from the base to the tip through flange <NUM>.

Lid-frame connectors <NUM> of this illustrative embodiment are frangible and are configured to break when lid <NUM> is moved from the first position toward the second position as described above in connection with assembly <NUM>. In this illustrative embodiment, pin <NUM> tears out of flange <NUM>, breaking flange <NUM>, during this movement. Each tab <NUM> may be pivotably coupled to its respective surrounding wall 316a, 316b, 316c, 316d so that, during movement from the first position to the second position, tab <NUM> pivots downward, which may encourage predictable and consistent separation (e.g., breakage) of lid-frame connector <NUM> (e.g., pins <NUM> tearing-out of flanges <NUM>).

Any exemplary frangible connectors described herein may include one or more stress risers arranged to encourage a particular failure mode, such as which component of the connector will break first and/or the location of the break. <FIG> illustrates an exemplary stress riser, specifically a notch <NUM>, in flange <NUM>. During staging (e.g., movement from the first position to the second position), the notch <NUM> may encourage breakage of the flange <NUM>, thereby facilitating predictable and consistent separation of the lid <NUM> from the peripheral portion <NUM> of frame <NUM>.

Claim 1:
A histologic tissue sample support device (<NUM>, <NUM>, <NUM>, <NUM>) comprising:
a tissue cassette (<NUM>, <NUM>, <NUM>, <NUM>) having a recess (<NUM>, <NUM>, <NUM>) including at least one side wall (12a, 112a, 212a) and a bottom wall (12b, 112b, 212b), the tissue cassette formed of a first material that can be successfully sectioned in a microtome and is resistant to degradation from solvents and chemicals used to fix, process and stain tissue;
a frame (<NUM>, <NUM>, <NUM>, <NUM>) including a bottom edge (14e, 114e, 214e), the frame formed of a second material different from the first material and more rigid than the first material, the tissue cassette being coupled to the frame by a frame-cassette connector (<NUM>, <NUM>, <NUM>, <NUM>) comprising a first retaining structure formed integrally with the frame and extending at least partway through a second retaining structure formed integrally with the cassette; and
a lid (<NUM>, <NUM>, <NUM>, <NUM>) coupled to the frame;
wherein the lid and the tissue cassette are capable of moving from a first position to a second position with respect to the frame, and in the second position, the bottom wall and at least a portion of the side wall extend downwardly beyond the bottom edge of the frame for sectioning in the microtome; and
wherein the frame is capable of being decoupled from the cassette by separating the frame-cassette connector.