Integral centrifuge tube and specimen slide

Abstract: A generally tubular container (12) is integrally formed with, and communicates with, a microscope slide member (14) having an enclosed specimens chamber. The container (12) serves both as a centrifugation tube and a permanent handle for manipulation of the microscope slide member (14). The back (18) of the device is generally flat and the front and sides (24) of the collection tube are generally rounded except for a concave region (26) extending longitudinally from the upper face (30) of the microscope slide terms (14) to provide clearance for rotating a lens turret for high power viewing of a specimen in the slide chamber.

Description: The present invention generally relates to an integral biological specimen collection tube and microscope slide constructed as a unitary device. Various types of laboratory devices have been devised in the past for the collection and processing of biological specimens. Complete urinalysis typically involves centrifugation of the specimen to isolate any sediment for microscopic study. Most procedures and devices currently in use require pouring the test liquid into a centrifuge tube and separately decanting the supernatant liquid from the sediment after centrifugation, then transferring the sediment to a microscope slide. Such procedures are time-consuming and expensive. Moreover, these individual steps are multiple in character, take the time of the technician, and increase the technician's contact with the specimen. There is a need for an improved type of device which can be used for initial biological liquid collection, subsequent centrifugation, sediment isolation and microscopic examination, all without transferring the test materials to other laboratory equipment. The present invention fulfills that need. With a view to fulfilling this need, we have proposed in EP-A-0 277 810 to provide an integral specimen collection tube and microscope slide device which includes an elongated tubular container portion having an entrance opening at a proximal end and an exit opening at a distal end, the container portion having a flat planar surface extending along a rear side thereof, a slide portion joined to the container portion at the distal end and in fluid communication therewith via the exit opening, the slide portion extending longitudinally beyond the container portion to a closed terminal end of the device, and a transition portion between the tubular container and slide portions for locating the slide portion base member relative to the planar surface adjacent the microscope stage when the device is placed on the stage with the flat rear side of the tubular container portion in contact with the stage, the slide portion having flat, optically transparent opposed parallel base and cover members defining a chamber for receiving a specimen and displaying same for viewing through a microscope having a slide supporting stage, the tubular container portion having a receding section along the side opposite the flat planar surface which extends from the juncture of the tubular container portion with the slide portion to a smooth transition into the cylindrical wall of the tubular container portion. Such a device as disclosed therein comprises an upper, hollow, generally tubular container which serves as a specimen collection member, having a central specimen collection space therein communicating with the open upper end of the container. The device also includes a lower integral microscope slide member having transparent flat front and rear walls throughout at least part thereof and defining a central specimen cavity communicating with the container space through the lower end of the container. The juncture between the generally tubular container portion and the slide member portion is a transition section in which the cross-section of the tubular portion reduces to match the cross-section of the slide portion. The container also serves as a permanent rigid handle for the microscope slide member. The tubular container portion of the device has a flattened side presenting a planar surface extending completely along the tubular container portion from the transition section to the open end of the container. The narrow lip projecting outward and extending about the open end of the tubular container portion is removed at the juncture with the planar surface. For convenience in orientation, the planar surface will be regarded as extending along the rearward side of the tubular container portion. A device according to the present invention is characterized in that the receding section recedes over a sufficient length to provide clearance for rotation of the lens turret of a microscope when the device is placed on the slide supporting stage with the flat rear side of the tubular container portion in contact with the stage In a preferred embodiment the slide portion of the device provides a viewing section extending approximately 5/8 inch (16 mm) beyond the transition section and centrally located between gradually diminishing tapered edges which are continuations of the tapered side surfaces of the tubular container portion. The upper and lower faces of the microscope slide portion are generally parallel and spaced apart by approximately .008 to .010 inches (.23 to .25mm), over the major part of the slide cavity. The upper face, which serves as a cover slip, is from .009 to .012 inch (.23 to .3mm) thick. The lower face of the slide portion is approximately .040 inch (1 mm) thick and, in one embodiment, is spaced just slightly from the plane of the flattened face of the tube portion, approximately 1/16 inch (1.6 mm), thus protecting the slide portion from possible scratching by any surface on which the device is placed with the flat side down. The slide portion of this device is displaced only slightly from the stage of a viewing microscope when the device is in position for viewing, thereby achieving optimum optical clarity for viewing. The enclosed space of the slide portion is sufficient to receive a normal sediment sample from a specimen placed in the tubular container portion while maintaining the - sediment sufficiently dispersed as to permit viewing thereof through a microscope. Preferably, a monomolecular layer of sediment is desired. However, sediment crystals in urine or blood platelets have a tendency to pack at the entrance of the slide portion if the aperture is too small. Thus, the aperture is slightly larger than the minimum size necessary to accommodate such sediment. Furthermore, the capability of the slide portion to receive the specimen sediment constituents is enhanced by the provision of two channels on opposite sides of the slide portion extending downwardly from the plane of the aperture. The width of these channels is approximately equal to the spacing in the slide cavity. These channels extend along opposite sides of the slide cavity to approximately the end of the cavity. These channels advantageously reduce the tendency of packing of crystals at the entrance portion of the slide cavity to block sediment from reaching the viewing section, since any sediment passing into the channels becomes distributed within the slide cavity. Although in one preferred embodiment, the channels depend downwardly from the slide cavity, other channel configurations are possible and suitable for the purpose. While the embodiment which has just been described may be characterized as an inverted U-shaped cross section, other configurations may be in the form of an I-shaped cross section or a H-shaped cross section, to name a few. The side channels may extend straight along the side edges of the slide cavity, terminating at the end of the cavity, as will be the case for injection molded plastic forms of the invention. Alternatively, it may be possible to have the side channels extend completely around the distal end of the slide cavity, joining together at the central axis of the cavity for thermoformed or blow-molded embodiments of the invention. Preferably, the integral centrifuge tube and specimen slide of the present invention is provided with a cap closure which may be used to close the open end of the device when the liquid specimen is placed therein. This is not an essential constituent of the combination, but where included it eliminates the otherwise necessary step of decanting the supernatant liquid from the specimen container after centrifuging before the sediment collected in the slide cavity may be viewed in normal fashion through a microscope. The cap is generally of the same cross sectional shape as the tubular container portion and matches the dimensions of the opening. It is formed with a pair of peripheral sealing ridges which protrude slightly from the cap body to provide an improved seal against the inner surface of the tubular container opening. Another desirable adjunct to the device of the present invention, although not essential to its normal use, is a funnel which is used by the patient in directing the specimen into the tubular container. Such a funnel is preferably thermoformed of a suitable closed cell foam material, approximately 1/16 inch thick, and sufficiently flexible to be packed flat. The cap may also be formed of the same material and integrally with the funnel. Thus the entire combination can be placed in a plastic envelope and distributed for marketing at minimum cost. With this arrangement, after removal from the plastic or paper envelope in preparation for use, the funnel is squeezed at the flattened side edges to restore its generally round shape and the short neck of the funnel is inserted into the opening of the tubular container. The cap is initially attached to the outside of the funnel. The liquid specimen is deposited within the funnel which directs it into the tubular container. Thereafter the cap is removed from the funnel, the funnel is removed from the tubular container and the cap is inserted to seal the opening thereof. For the collection of urine specimens, the combination in accordance with the present invention provides a urine transport system which automatically prepares a microscope slide by centrifuging a specimen. On the front side of the tubular container portion, opposite the rearward planar surface, is a gradually receding section which curves smoothly and continuously from a juncture with the upper face of the slide portion to a point approximately 5 cm (2 inches) from the center of the slide portion where it smoothly transitions into the slightly tapered cylindrical shape of the tubular container portion. This results in a generally flattened section of varying thickness of the tubular contained portion which provides clearance to permit changing of the magnification level of a microscope when the microscope slide portion is in a position for viewing without the necessity of temporarily removing the device while the magnification level is adjusted. Thus, the lens turret of a multi-lens microscope may be rotated while the device of the present invention is in place for viewing of the slide portion without encountering any interference or obstruction from the integral tubular container portion. The device of the present invention may be readily molded in modern plastic molding equipment, is esthetically pleasing in appearance, is effective in use in centrally positioning and displaying the sediment from a centrifuged specimen for microscope viewing, and is low in cost and reliable in use so as to be readily disposable after a single use. In the accompanying drawing: FIG. 1 is a perspective view of the preferred embodiment in accordance with the present invention; FIG. 2 is a side sectional view of the device of FIG. 1; FIG. 3 is an enlarged sectional view of a portion of FIG. 2; FIG. 4 is a view of the device of FIG. 1, taken from the left-hand or open top end; FIG. 5 is a view of the device of FIG. 1, taken from the right-hand or closed bottom end; FIGS. 6A and 6B are, respectively, side and end views of a cap for the device of FIG. 1; FIGS. 7A and 7B are, respectively, side and end views of a collapsible funnel and cap for use with the device of FIG. 1; FIGS. 8A-8C are cross sectional views showing alternative shapes for the slide portion of the device of FIG. 1, including side channels; FIGS. 9A-9C are partial plan views of a slide portion of the device of FIG. 1 showing alternative outline shapes of the channels associated therewith; and FIGS. 10A and 10B are partial side sectional views of alternative embodiments of the device of the present invention. A first preferred embodiment of the improved unitary specimen collection tube and microscope slide device of the present invention is schematically depicted in FIGS. 1 and 2. FIGS. 4 and 5 are, respectively, left end and right end elevational views of the device of FIGS. 1 and 2. It will be understood that the device could also be used for other purposes, such as in the the chemical analysis of inorganic materials and the like, but has its greatest applicability to laboratory analysis of specimens such as urine, blood and like biological fluids. Device 10 comprises a tubular container portion 12 and a specimen slide portion 14 on opposite sides of a transition section 16. Device 10 is transparent and comprises a flat rear wall 18 running the length of the container portion 12. The container portion has a lip 20 which projects circumferentially about the open end 22, except along the edge of the rear wall 18. The tubular container portion 12 is further divided into a slightly tapered, generally cylindrical (except for the flat rear wall 18) section 24 and a gradually receding clearance section 26 which curves radially inwardly from a juncture with the generally cylindrical section 24 to merge with the upper face 30 of the slide portion 14. The section 26 constitutes a "high power curve" which permits shifting the turret of a multi-lens microscope for different levels of viewing power and, in the embodiment shown in FIG. 1, is a generally transversely flat, longitudinally curved, concave surface which is a continuation of the upper face 30 of the slide portion 14. As indicated in the enlarged cross-sectional view of the slide portion 14 in FIG. 3, the upper face 30 and lower face 32 are essentially parallel and define between them a thin chamber 34 which is closed at the distal end 36. The slide portion 14 is much like a standard microscope slide bearing a mounted specimen, the lower face 32 being approximately 1 mm (.040 inch) in thickness and corresponding to the slide proper. The upper face 30 is approximately 0.23 to 0.3 mm (.009 to .012 inches) thick and corresponds to a slide cover slip. The chamber 34 is approximately 0.2 to 0.25 mm (.008 to .010 inch) thick and contains the mounted specimen. The high power curve section 26 is essentially tangent to the flat upper face 30 where they join and merges into it at approximately the transition section 16. FIG. 4 is an end view of the device 10 as it appears viewed from the left-hand end, as shown in FIGS. 1 and 2, through the opening 22. FIG. 5 is an end view of the device 10 taken from the opposite, closed end. The view of FIG. 4 shows a pair of side channels 38 which extend generally along opposite sides of the chamber 34. These side channels 38 preferably extend to the end 36 of the chamber 34. Although the device 10 could be constructed without the channels 38, they perform an important function in the automatic preparation of the specimen slide by alleviating the tendency of the specimen particles, such as crystals in a urine specimen, to pack up and develop a blockage at the entrance to the chamber 34. The channels 38 serve to provide additional passageways for the sedimentary particles which are then enabled to migrate in to the central portion of the chamber 34 from the sides as well as through the transverse opening 40 in the vicinity of the transition section 16. With such an arrangement, the resulting specimen in the microscope slide chamber is very close to the desired monocellular array in thickness. These side channels 38, taken with the chamber 34, may form different configurations of which a few are shown in FIGS. 8A-8C. The chamber opening in the cross-sectional view of FIG. 8A may be described as an inverted U-shape and corresponds to the configuration depicted in FIG. 4. FiG. 8B shows a cross-sectional configuration which is generally I-shaped and has side channels 38' with open portions extending both above and below the chamber 34' by essentially equal amounts. FIG. 8C depicts an H-shaped cross-section in which the side channels 38'' extend downwardly from the chamber 34'' by approximately the same amount as shown in FIG. 8A but extend upwardly from the chamber 34'' less than in FIG. 8B. FIGS. 9A-9B are schematic plan views of alternative slide portions 14 having channels 38, 38A, and 38B, respectively, of different shapes as viewed from above. In FIG. 9A, the side channels 38 extend straight along to the end 36 on opposite sides of the chamber 34. This is the configuration generally preferred for devices of the invention which are prepared by injection molding. FIG. 9B shows a generally V-shaped channel 38A which extends across the chamber 34. FIG. 9C shows a generally U-shaped channel 38B which extends along the sides and across the bottom of the chamber 34. The configurations of FIG. 9B and 9C may be feasible for devices of the present invention which are formed by other than injection molding; e.g., thermoforming. FIGS. 6A and 6B depict an optional cap closure for the open end 22 of the device 10. The cap 50 may be thermoformed of an inexpensive plastic material to have a peripheral lip 52, generally matching the lip 20 of the device 10, and a pair of circumferential, outwardly protruding, sealing rings 54. In the use of the device 10, cap 50 is placed in position to close the open end 22 of the device 10. Since this sealingly closes the opening 22, the device 10 may be laid down on its flat surface 18 or may be handled in any attitude without concern that the liquid portion of the specimen will run out. The cap 50 is designed to be discarded with the device 10 when the microscope analysis of the specimen in the chamber 34 has been completed. If desired, the cap 50 may be integrally formed as part of a flexible plastic funnel 60 which is shown in FIGS. 7A and 7B. Funnel 60 is shown comprising a receiver portion 62 and neck portion 64. As indicated in FIG. 7B, the flexible funnel 60 is designed to be folded essentially flat for inclusion with a device 10 in a sterile specimen kit packaged in a transparent plastic bag (not shown). When formed in this manner, the cap 50 is affixed to the funnel 60 by a thin, easily severable, threadlike segment 56. In preparation for use, the patient will remove the funnel 60 from the flat pack and squeeze the folded edges 66 to restore the funnel 60 to a generally circular configuration. The neck 64 is then placed within the open end 22 of the device 10 and a sample, such as urine, is deposited within the receiver portion 62 and directed into the tubular container of the device 10. When the specimen has been deposited within the device 10, the funnel 60 may be removed and the cap 50 detached from the funnel 60 and inserted into the end opening 22. Thereafter, the device 10 with the contained sample is ready for centrifuging to automatically prepare the specimen within the microscope slide portion of the device 10. The transition portion 16 of the device 10 may be varied in shape to suit the purpose. FIG. 10A shows an enlarged side sectional view of the terminal end portion of the device 10. In FIG. 10A, the flat rear face 18 extends all the way to the end 36 in the same plane, thus avoiding the offset of the transition portion 16 as it appears in FIG. 3. Reference numeral 40 indicates the opening of the chamber 34 at the point at which the high power curve surface of the clearance section 26 joins the upper face 30 of the microscope slide portion 14. FIG. 10B shows another configuration of the offset at the transition portion 16′. In the view of FIG. 10B, the transition portion 16′ has a generally S-shaped curved cross-section rather than the zig-zag, somewhat Z-shaped, configuration of FIG. 3. In injection molding the device 10 of FIG. 10B, the gently radiused curves of the transition portion 16′ allow the plastic to flow more smoothly into the slide portion 14, thus applying less transverse force against the blade which constitutes the terminal end of the male part of the die used in the injection molding and thus reducing the likelihood that the blade will be displaced from its proper location within the mold.

Claims: An integral specimen collection tube and microscope slide device (10) which includes an elongated tubular container portion (12) having an entrance opening (22) at a proximal end and an exit opening (40) at a distal end, the container portion having a flat planar surface (18) extending along a rear side thereof, a slide portion (14) joined to the container portion (12) at the distal end and in fluid communication therewith via the exit opening (40), the slide portion (14) extending longitudinally beyond the container portion (12) to a closed terminal end (36) of the device, and a transaction portion (16) between the tubular container and slide portions for connecting the slide portion base member (32) to the planar surface (18), the slide portion (14) having flat, optically transparent, opposed parallel base (32) and cover (30) members defining a chamber (34) for receiving a specimen and displaying sane for viewing through a microscope having a slide supporting stage, the tubular container portion having a receding section (26) along the side opposite the flat planar surface (18) which extends from the juncture of the tubular container portion (12) with the slide portion (14) to a smooth transition into the cylindrical wall (24) of the tubular container portion (12), characterized in that the receding section recedes over a sufficient length to provide clearance for rotation of the lens turret of a microscope when the device (10) is placed on the slide supporting stage with the flat rear side (18) of the tubular container portion (12) in contact with the stage. The device of claim 1 further characterized by the receding section (26) having a generally transversely flat, longitudinally curved, concave surface which is a continuation of the cover member (30) and extends approximately 5 centimeters from the center of the slide portion to the transition into the cylindrical wall (24) of the tubular container portion (12). The device of claim 2 further characterized by the concave surface extending generally tangentially from the proximal end of the cover member (30). The device of claim 2 or claim 3 further characterized by the concave surface merging with the cover member (30) in the vicinity of the transition portion (16). The device of claim 4 further characterized by the concave surface merging with the tubular container portion (12) adjacent the longitudinal midpoint of the tubular container portion (12). The device of any one of claims 1-5 further characterized by the slide portion base member (32) constituting a co-planar extension of the flat planar surface (18) along the rear side of the container portion (12). The device of any one of claims 1-5 further characterized by the slide portion base member (32) being parallel to but displaced slightly from the plane of the flat planar surface (18). The device of any one of claims 1-5 and 7 further characterized by the transition portion (16) comprising a generally Z-shaped segment defining a wall joining the base member (32) to the flat planar surface (18). The device of any one of claims 1-5 and 7 further characterized by the transition portion (16) comprising a generally S-shaped wall (16') having radiused terminal segments joining the base member (32) and the flat planar surface (18). The device of any one of claims 1-9 further characterized by the chamber (34) being bounded by closed side edges of the slide portion (14) and by the closed terminal end (36) and having an opening along a proximal end of the slide portion communicating with the exit opening (40) of the tubular container portion. The device of any one of claims 1-10 further characterized by the chamber (34) including at least one channel (38) extending from the chamber entrance opening (40) along a major extent of the chamber (34) to facilitate the movement of specimen particulates into said chamber (34) and effect a more even distribution therein. The device of any one of claims 1-10 further characterized by the chamber (34) including a pair of elongated channels (38,38',38'') extending longitudinally of the chamber along opposite edges thereof. The device of claim 12 wherein the pair of channels (38) continue to a junction (38B) with each other across the terminal end of the chamber (34). The device of claim 11 wherein the channel (38A) is generally V-shaped and extends longitudinally of the chamber (34). The device of claim 11 wherein the opening of the chamber (34) and channel (38) is configured in a generally U-shaped transverse cross-section. The device of claim 11 wherein the opening of the chamber (34') and channel (38') is configured in a generally I-shaped transverse cross-section. The device of claim 11 wherein the opening of the chamber (34'') and channel (38'') is configured in a generally H-shaped transverse cross-section. The device of any one of claims 1-17 further characterized by the slide portion forming a sandwich configuration including the chamber (34) and the base (32) and cover (30) members with the base member (32) being approximately 1 mm. thick, the chamber (34) being approximately .2 to .25 mm. thick, and the cover member (30) being approximately .23 to .3 mm. thick, the sandwich configuration being approximately 1.5 mm. thick.

Inventors: MULLER LOUIS FREDERICK, MULLER, LOUIS FREDERICK
Applicants: DAVSTAR CALIFORNIA INC, DAVSTAR CALIFORNIA, INC.
Application year: 1989
Main classification: B01L3
IPC codes: G01N33, B01L3, G01N1, G02B21