Abstract:
A method for simultaneously processing a plural number of samples, each held in its own container and including a fluid containing particulate matter. Each of the containers with its respective sample therein is closed by a respective cover assembly comprising a pump, a filter interposed between the container and the pump, and an agitator projecting into its respective sample. Each container is engaged by a separate container receiver, each pump is engaged by a separate pump receiver, and the container receivers are moved relative to the pump receivers simultaneously to mix the samples. Thereafter all of the pump receivers are moved relative to the container receivers to operate all of the pumps simultaneously to move the fluid of each sample through its respective filter.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a division of U.S. Ser. No. 09/185,606, filed Nov. 4, 1998 which claims the benefit of priority based on U.S. Provisional Application Ser. No. 60/064,271, filed Nov. 4, 1997. 
    
    
     TECHNICAL FIELD OF THE INVENTION 
     The present invention is directed to an apparatus and method for collecting a uniform monolayer of particulate matter. In particular, the present invention is directed to an apparatus and manual or semi-automatic method for collecting a uniform monolayer of cells from biological fluids and preparing the monolayer of cells for use in cytological protocols. 
     BACKGROUND OF THE INVENTION 
     In a wide variety of technologies, the ability and/or facility for separating matter, typically particulate matter, from a fluid is a critical component in the ability to test for the presence of substances in the fluid. Too often, interference associated with sample preparation obscures the target cells to such a degree that the process is not sufficiently reliable, or too costly. 
     Such a scenario applies to many other fields which involve detection and/or diagnosis, including environmental testing, radiation research, cancer screening, cytological examination, microbiological testing, and hazardous waste contamination, to name just a few. 
     In all of these endeavors, limiting factors in the sample preparation protocol include adequately separating particulate matter from its fluid carrier (e.g., physiological fluid, biological fluid and environmental fluid), and easily and efficiently collecting and concentrating the particulate matter in a form readily accessible for microscopic examination. 
     In the case of cytological examination, a sample of cells is obtained from a patient. Typically, this is done by scraping or swabbing an area, as in the case of cervical samples, or by collecting body fluids, such as those obtained from the chest cavity, bladder, or spinal canal, or by fine needle aspiration. In a conventional manual cytological examination, particulate matter including cells and debris in the fluid are transferred onto a glass slide by smearing and subsequently air-dried. Smearing results in non-uniform densities and uneven distributions of cells and debris that often obscure the target cells. Air drying causes cell distortion and further impedes accurate examination. 
     It has been found that prompt processing of urine to obtain fresh ensures the accuracy of quantitative culture results, urinalysis and microscopy. Fresh cells tend to stick to a glass slide much better than cells from preserved urine, allowing for smoother cell spread onto the glass body. Delays in processing, negligent care in either inpatient or outpatient settings and lack of refrigeration may lead to non-optimal slide preparation. One known solution to the delay problem is the use of chemical preservatives with the urine. The presence of liquid preservatives, however, in the urine specimen raises the specific gravity of the specimen to unmeasurable levels and may limit the potential usefulness of the urine for various types of traditional quantitative analysis, such as slide microscopy. 
     Diagnostic microbiology and/or cytology, particularly in the area of clinical pathology, bases diagnoses on a microscopic examination of cells and other microscopic analyses. The accuracy of the diagnosis and the preparation of optimally interpretable specimens typically depends upon adequate sample preparation. New methodologies such as immunocytochemistry and image analysis require preparations that are reproducible, fast, biohazard-free and inexpensive. Conventional cell preparation techniques fail to adequately address the issues of non-uniform cell densities, uneven cell distribution and air drying artifacts. 
     Conventionally, body fluid samples are collected for cytological examinations using containers that contain a preservative solution for preserving the cytology specimen during shipment from the collection site to the cytology laboratory. Furthermore, cytology specimens collected from the body cavities using a swab, smear, flush or brush are also preserved in containers with fixatives (e.g., alcohol or acetone fixatives) prior to transferring cells onto the slide or membrane for staining or examination. 
     It is desirable to provide a urine or other biological fluid specimen container that would allow liquid biological specimens to be tested without removing the lid of the urine or biological fluid container. However, none of the prior art solves the problems of transferring cells in a monolayer to a slide for examination without submerging portions of the device in the sample (and increasing the risk of contamination), consistently and repeatedly forming a high quality monolayer on the microscope slide, and processing the sample so that the fluid from which the cells were taken is preserved. 
     A number of methods, apparatuses, and structures for dispersing cells in the fluid are known. For example, U.S. Pat. No. 5,143,627 opens the sample container, inserts a dispersing element into the liquid suspension, and rotates the dispersing element for several minutes. In another example, the so-called “Saccomanno method” is used to process sputum, a process that is time consuming and involves a large number of processing steps. 
     In contrast to the conventional techniques, the solid matter preparation techniques of the present invention address the issues of non-uniform matter densities, uneven matter distribution, and sample loss and contamination due to the number of steps involved in the sample preparation. Thus, preparations according to the present invention result in an even distribution of solids that have superior morphology, improved visualization, and are readily positioned and available for light absorbance analysis without the need to further manipulate or prepare the sample. 
     SUMMARY OF THE INVENTION 
     The present invention relates to an apparatus and method for collecting matter for detection, analysis, quantification, and/or visualization. The devices and methods of the present invention are particularly suitable for separating particulate matter from biological, physiological, and environmental fluids and presenting the particulate matter in an improved manner for cytological examination. 
     A preferred embodiment of the present invention relates to an apparatus and method for collecting a uniform layer of cells from urine or other biological fluid specimen in a cytology collection apparatus or assay module, and for transferring the uniform layer of particulate matter to a slide. 
     The devices and methods of the present invention may be configured into a hand-held manual system or structure, or a partially automated system or structure. 
     Such an apparatus according to the present invention overcomes the problems associated with conventional equipment for collecting cells and other particles for cytology by providing a mechanism of relatively simple structure and operation that separates particles from a liquid solution, collects an approximately known quantity of the cells in a monolayer, and transfers the collected cells to a microscope slide. In some embodiments of the present invention, no element of the apparatus is placed in the liquid sample, thus preventing unnecessary contamination of the sample. Moreover, in some embodiments of the present invention, the container holding the sample is not opened in the course of collecting and transferring the cells, thus eliminating the possibility of sample contamination during testing. 
     In all embodiments of the present invention, a monolayer of the particulate matter, e.g., cells, in the sample is collected on a filter by passing two branches of a fluid flow through and around the filter. Such a filter is known from U.S. Pat. Nos. 5,301,685 and 5,471,994, which are incorporated by reference. 
     The patient or medical person handling the collection may seal a separate container. The collection of the cells according to the present invention allows a uniform cell slide to be obtained without contamination of the cells by preservatives, workers or outside materials. The transfer from collection container to the cytology collection apparatus may be carried out without pouring or pipetting the collected specimen. 
     The present invention is directed to a cell collection and distribution apparatus that can be disassembled to allow face to face transfer of cells from the device to a slide for microscope examination. The present invention provides an improved apparatus and method for collecting a monolayer of cells that can be transferred to a microscope slide. The effectiveness of transferring the monolayer cells from the filter to a microscope slide has proven to be very high without differential cell loss. Microscopic examination shows that the cell distribution is the same on the slide as on the filter. 
     The devices of the present invention obviate the need for a trained technician to properly prepare a sample substrate. Thus, time, expense, and expertise are eliminated or reduced as critical factors in sample preparation protocols. 
     The devices and methods of the present invention also provide advantages in sample preparation because they are suitable for use with fresh, untreated cells, unmodified cells, and are particularly designed to provide a thin, uniform layer of solid matter (up to approximately 40 microns or more). This invention is particularly useful for collecting cells for a Pap smear. 
     The apparatuses and methods of the present invention have many advantages for conventional microbiology and hematology. The collected cells are in a pre-determined area that is easily accessible to a radiant light source and to a wavelength absorbance meter. Because cells are concentrated in a single layer, they are almost always in one focal plane, thus eliminating or reducing interference by other particles and virtually eliminating technician time and expertise in establishing a proper reading. The minimal matter overlap achieved by the present invention ensures that all matter can be easily examined with little chance for critical solids to be obscured by clumps of overlapping solids or debris. Certain embodiments of the apparatuses of the present invention may be used in combination with other automated devices to detect and analyze any solid matter in a given population. They also permit a detailed analysis of the chemical composition of the matter. 
     The present invention also includes an improved apparatus and method for processing a fluid containing particulate matter. The apparatus and method include dispersing particulate matter in the sample, preferably by rotating the sample container around a fixed agitator or by rotating the agitator inside a fixed sample container. The present invention agitates the sample within the container to ensure break-up of large particulate matter, e.g., mucoid bodies in the case of sputum samples, and the even distribution of cells throughout the fluid. Agitation may occur as the result of relative motion between components of the sample container, non-uniform motion of the sample container, and/or inertial reaction forces applied to the sample by the container. 
     According to a preferred embodiment of the present invention structures and means are provided for rotating an agitator in relation to the container and/or the sample in the container. As described in more detail below, a preferred embodiment according to the present invention may include a cover within a cover, wherein the agitator is fixed to a freely rotatable outer cover and an inner cover is secured with respect to a stationary sample container. Such relative motion moves the agitator in relation to the sample, and disperses particulate matter in the fluid. 
     Further, providing a container cover that has a portion that is rotatable permits particulate matter stirring or dispersion without inserting a stirring mechanism into the sample, thus eliminating a source of contamination that plaques devices that are presently commercially available. In preferred embodiments of the present invention, the covering on the sample container may include a hollow tube, with or without a rotatable dispersing element, for withdrawing the sample from the container. 
     In a preferred embodiment of the invention, the cover comprises a first portion that fixedly engages the container and a second portion that may be rotatable in relation to the container. As used herein, rotatable in relation to the container refers to the relative movement of the first portion and the second portion; the first portion may be fixed and the second portion moveable, or the first portion may be moveable and the second portion fixed. In a most preferred embodiment, the second or inner portion of the cover is stationary and the first or outer portion is rotatable. In a preferred embodiment of the invention, the agitator is engaged by or fixed to the second portion of the cover. 
     An apparatus according to a preferred embodiment of the present invention may be configured to support, engage, and rotate a portion of a collection container so that the sample is mixed according to the present invention. An exemplary collection container includes a container or cup suitable for collecting and holding a specimen sample, a cap having a first position that is not rotatable in relation to the container and a second position that is rotatable in relation to the container, and an agitator engaged by or fixed to a portion of the cover and extending into the container. As used herein, configured to support, engage, and rotate refers to various configurations that may be adapted to perform the specific function. For example, an apparatus according to the invention may include a container support for positioning at least one sample container and rotating the container per se, and a sleeve or clamp for engaging and fixing a portion of the cap that communicates with an agitating element. Alternatively, the support may hold the container in a fixed position and a pulley, sleeve, or clamp may engage and rotate the portion of the cap that is fixed with respect to an agitator. In a preferred embodiment of the invention, a sleeve engages an inner portion of the cap, and holds the inner portion of the cap in a stationary position in relation to an outer portion of the cap. 
     Configurations or structures that engage a portion of the cap or the container typically include any member that positions, fixes and/or moves either that portion of the cap or the container. Exemplary members include, but are not limited to, a sleeve, one or more belts, one or more pulleys, one or more resilient bands, and the like. 
     The present invention is also a device for processing a fluid into one or more components, typically by removing particulate matter from the fluid. The present invention is directed to apparatuses and methods for collecting fluids, such as biological, physiological, or environmental fluids, and removing particulate matter from the fluid, without centrifugation, and diagnosing and testing the matter. In a preferred embodiment of the invention, particulate matter is collected on a collection site. In a most preferred embodiment of the invention, the particulate matter is collected in a monolayer and in a pre-determined spatial arrangement. 
     While a cytology collection apparatus according to the invention can be used for any biological fluid, it is particularly useful for preparing testing samples from urine and its associated cells for Pap smears. It is intended that the type of matter being processed should not limit the invention. In a most preferred embodiment of the invention, the fluid is urine and particulate matter is a cell. The particulate matter processing apparatus of the present invention also permits isolation and collection of fresh cells and/or microorganisms from biological fluids to perform DNA probe and chromosomal analysis once the proper buffer hemolyzes the cells. 
     In the case of cervical examinations, a scraping of the cervix is taken with a longhandled brush or broom. The handle is then shortened, such as by breaking or telescopic movement, and the brush is inserted into a specimen container. Conventionally, the container must be opened to remove the brush at the time of testing. Such a process increases the likelihood of contamination because the cover of the sample container must be opened, the brush typically retains cells if the testing is not performed soon after cell collection, and the operator must come into contact with the sample. 
     According to a preferred embodiment of the present invention, these problems are avoided by providing a system in which the brush not only remains in the collection container, but can also be used to disperse the collected cells during agitation. Further, the apparatus of the present invention is a closed system; once the apparatus is closed, it does not need to be opened in order to process any cells collected on the brush. 
     Further, providing a container cover that has a portion that is rotatable permits particulate matter stirring or dispersion without inserting a stirring mechanism into the sample, thus eliminating a source of contamination that plaques devices that are presently commercially available. 
     The present invention is also directed to a cytology collection and testing kit containing a cytology collection apparatus, replacement filters, replacement disposables, and/or other components, ingredients of a fixative composition as described below. The cytology collection kit may also include replacement filters, replacement disposables, and/or other components, ingredients or solutions typically used during cytological examinations. The kit might also include washing, fixative, and/or buffer solutions. A cervical kit may include a brush or broom, and a fluid suitable for storing the used brush until particulate matter on the brush can be processed through the filter assembly. 
     According to another aspect of the present invention, the matter collection apparatus may also include additional modules, removable or integrated, for treating the fluid. For example, the fluid may be treated with a matter collection module, in combination with a debris removal module, a chromatography module, and assay module, or combinations of these and other devices. These and other modules or treatment protocols provide features that may be desirable to incorporate into a sample preparation apparatus according to the invention. 
     The devices and methods of the present invention have many advantages for conventional cytology. The cells are in a pre-determined area allowing for significant timesaving when screening the slide. Such problems as cells lying outside the coverslip or on the frosted end are eliminated. Because cells are lying in a single layer, they are almost always in a one focal plane when using a 10×objective—the objective most often used for the lower power screening of a slide. Even with a 40×objective, most cells are in focus. This eliminates frequent refocusing and saves time. 
     The objects of the present invention are achieved by an apparatus for simultaneously processing a positive whole number of samples wherein each of the samples includes a fluid containing a respective particulate matter. The apparatus comprises a number of containers corresponding to the number of samples, each of the containers being adapted for holding a respective sample; a number of pumps corresponding to the number of samples, each of the pumps being adapted for communicating a respective fluid with a respective container; a number of filters corresponding to the number of samples, each of the filters being interposed between a respective pump and its respective container and being adapted for collecting a respective particulate matter; a first engagement supporting each of the containers, the first engagement having a number of first receivers corresponding to at least the number of samples, each of the containers being contiguously engaged by a respective first receiver; and a second engagement retaining the pumps, the second engagement having a number of second receivers corresponding to the number of first receivers, each of the pumps being contiguously engaged by a respective second receiver. Relative movement between respective ones of the first and second receivers disperses a respective particulate matter in its respective fluid. 
     The objects of the present invention are also achieved by a method for simultaneously processing a number of samples wherein each of the samples are held in a respective container and include a respective fluid containing a respective particulate matter. The method comprises closing each of the containers with a respective pump, each pump including a respective filter being interposed between its respective container and its respective pump and being adapted for collecting its respective particulate matter; supporting each of the containers on a first engagement, the first engagement having a number of first receivers corresponding to at least the number of samples, each of the containers being contiguously engaged by a respective first receiver; retaining the pumps on a second engagement, the second engagement having a number of second receivers corresponding to the number of first receivers, each of the pumps being contiguously engaged by a respective second receiver; and moving respective ones of the first receivers relative to respective ones of the second receivers for dispersing its respective particulate matter in its respective fluid. 
     The accompanying drawings show illustrative embodiments of the invention from which these and other of the objectives, novel features and advantages will be readily apparent. 
    
    
     DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a cross section view of a first preferred embodiment of the present invention. 
     FIG. 2 is a cross section view of the particulate matter separation chamber according to the present invention. 
     FIG. 3 is a cross section view of the fluid flow paths through the particulate matter separation chamber. 
     FIG. 4A is a top view of the base and well assembly, forming the bottom portion of the particulate matter separation chamber. 
     FIG. 4B is a top view of the bottom portion of the particulate matter separation chamber, and illustrates a clock face surface modification of the well. 
     FIG. 4C is a top view of the bottom portion of the particulate matter separation housing, and illustrates cross hatch face surface modification of the well. 
     FIG. 5 is a cross section view of a disassembled base, hollow tube, and container. 
     FIG. 6 is a bottom view of the top portion of the particulate matter separation housing. 
     FIG. 7 is a cross section view of the bottom portion of the particulate matter separation housing, and shows the optional channel and optional flap. 
     FIG. 8 is a cross section view of the bottom portion of the particulate matter separation housing, and shows the optional channel and optional O-ring. 
     FIG. 9 is a cross section view of the bottom portion of the particulate matter separation housing, and shows the optional channel and optional flap. 
     FIG. 10 is a cross section view of a second preferred embodiment of the present invention. 
     FIG. 11 is a cross section view of a third preferred embodiment of the present invention. 
     FIG. 12 is a combination of bottom and side views of a filter arrangement according to a preferred embodiment of the invention. 
     FIG. 13 is a cross section view of an apparatus used in a semi-automatic method according to a first preferred embodiment of the present invention. 
     FIG. 14 is a schematic illustration of the apparatus shown in FIG. 13 in a first position. 
     FIG. 15 is a schematic illustration of the apparatus shown in FIG. 13 in a second position. 
     FIG. 16 is a rendering of a mixing apparatus used in a semi-automatic method according to a second preferred embodiment of the present invention. An upper platform of the mixing apparatus is shown in its upper or open configuration. 
     FIG. 17 is a rendering of the mixing apparatus shown in FIG. 16 showing the upper platform in its lower or closed configuration. 
     FIG. 18 is a top view of the mixing apparatus shown in FIG.  16 . 
     FIG. 19 is a side view of the mixing apparatus shown in FIG.  16 . 
     FIG. 20 is a bottom view of the mixing apparatus shown in FIG. 16 showing an exemplary drive mechanism. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The present invention is a specimen container that includes a particulate matter separation chamber or module in fluid communication with a specimen container. 
     The present invention is also a device for processing a fluid into one or more components, typically by removing particulate matter from the fluid. 
     The present invention also includes devices and methods for collecting fluids, such as biological, physiological, or environmental fluids, removing the desired particulate matter from the fluid, without centrifugation, and diagnosing and testing the particulate matter. In a preferred embodiment of the invention, particulate matter is collected on a collection site. In a most preferred embodiment of the invention, the particulate matter is collected in a monolayer and in a pre-determined spatial arrangement. 
     The present invention also includes an improved apparatus and method for processing a fluid containing particulate matter. The apparatus and method include passing the fluid through a particulate matter separation chamber having a seat for a porous filter arrangement, the seat includes structures for aligning the collected particulate matter in a pre-determined spatial arrangement, structures that enhance the fluid flow through the particulate matter separation chamber, and/or structures that promote or retain the porosity and/or compression of the porous filter arrangement housed in the particulate matter separation chamber. 
     The present invention is also an improved device for collecting a processing a fluid, typically a biological fluid. The device includes a particulate matter separation chamber having one or more of the following: a collection site; a porous filter arrangement including a membrane for separating particulate matter from a fluid and a porous support frit; the porous filter arrangement establishes at least two fluid flow paths through the particulate matter separation chamber; a chamber seat that configures the collected particulate matter in a pre-determined spatial arrangement; a particulate matter separation chamber having a concentric channel; a channel having one or more resilient members; a chamber seat having one or more resilient members; a chamber seat or base having posts; a chamber seat having one or more pre-determined surface modifications; a chamber seat having one or more elements that promote a pre-determined spatial arrangement of particulate matter on the collection site; and structures that enhance the fluid flow through the particulate matter separation chamber. 
     A device according to the present invention may also include structures that are configured for and/or are adapted to mix the specimen collected in the specimen container. Exemplary structures include, but are not limited to, a specimen container having a cap, or a portion of the cap, that is relatively rotatable; a cap or cap portion that is moveable in relation to the specimen container; and a tube or the like that extends into the specimen container. The tube may include one or more elements for agitating the specimen. The cap may also include a portion that fittingly engages a portion of a cover for particulate matter separation chamber in a liquid tight seal. The cap may also include a portion that fittingly engages a portion of the cover in a liquid-tight but not fluid-tight seal. 
     A device according to the invention may also include a pump or syringe. The pump or syringe may optionally include one or more elements configured to permit a pre-determined amount of fluid into the pump or syringe. 
     The present invention also includes preparing a specimen for microscopic examination by processing a fluid using a device according to the invention, and collecting particulate matter on a collection site in the device. 
     The present invention also includes a method for analyzing matter comprising collecting a fluid in a chamber, collecting particulate matter on a collection site, and transferring the particulate matter collected on the collection site to a microscope slide or the like. Preferably, both collecting steps occur within the chamber. 
     A device according to the present invention may also include one or more separable elements. In a preferred embodiment of the invention, the device includes a separable particulate matter separation chamber. In a most preferred embodiment of the invention, the device includes a porous filter arrangement at least partially retained in a top portion of the chamber. 
     The present invention also includes a kit having an assay module that includes a particulate matter collection element according to the invention, a fluid specimen container, and a pump for inducing fluid flow from the specimen container through the assay module. 
     In a preferred embodiment of the invention, a fluid specimen in a container is in fluid communication with a particulate matter separation chamber or module for separating particulate matter in the fluid and collecting the separated particulate matter in a collection site. In a most preferred embodiment of the invention, the separated particulate matter is collected in a monolayer on the collection site. A preferred embodiment of the invention also includes a hollow tube providing fluid communication between the specimen container and the particulate matter separation chamber. More preferably, the hollow tube includes means for agitating the specimen and/or dispersing the particulate matter in the specimen. 
     In another embodiment of the invention, the apparatus includes the specimen container and particulate matter separation chamber described above, and a pump, syringe or the like. In this embodiment of the invention, various structures provide a fluid flow path from the specimen container, through the particulate matter separation chamber, and into the pump or syringe. 
     As used herein, the terms “sample” or “specimen” refer to any fluid in combination with solid matter, such as particulate matter, and from which it may be desirable to collect the particulate component from the sample for the purpose of establishing its identity or presence in the sample. Typically, the fluid component of the sample will be a liquid. However, the fluid may also be air or gas. As an example, it may be desirable to determine the presence of cancer cells or certain proteins in the biological fluid, such as urine. In another example, it may be desirable to evaluate the nature of contaminants, such as molecular contaminants, in ultra-pure water used in the electronics industry. Other exemplary fluids include but are not limited to body fluids, such as blood, spinal fluid, or amniotic fluid; bronchial lavage; sputum; fine needle aspirates; ground water; industrial processing fluids; and electronic or medical dialysis fluids, to identify just a few. It is intended that the type of fluid being processed should not limit the invention. 
     As used herein, the term “fluid” refers to any fluid for which it may be desirable to collect a component of the fluid for the purpose of establishing its identity or presence in the fluid. Typically, the component in the fluid will be a solid matter, such as particulate matter. For example, the fluid may be air or gas, or a biological fluid, such as urine, and it may be desirable to determine the presence of cancer cells or certain proteins in the biological fluid. In another example, it may be desirable to evaluate the nature of contaminants, such as molecular contaminants, in ultra-pure water used in the electronics industry. Other exemplary fluids include but are not limited to body fluids, such as blood, spinal fluid, or amniotic fluid; bronchial lavage; sputum; fine needle aspirates; ground water; industrial processing fluids; electronic or medical dialysis fluids; to identify just a few. It is intended that the type of fluid being processed should not limit the invention. 
     As used herein, the term “particulate matter” refers to any substance in a fluid that is capable of collection and evaluation, preferably by cytological examination. Exemplary particulate matter includes, but is not limited to cells or cell fragments, proteins, molecules, polymers, rubbers, stabilizers, antioxidants, accelerators, silicones, alkyds, thiokols, paraffins, thermoplastics, bacteria, pesticides, and herbicides. Specific exemplary polymeric matter include, but is not limited to polyethylene, polypropylene, polyisobutylene, polyacrylonitrile, polyethylene glycol, polyvinylchloride, polystyrene, polysulfide, polymethylmethacrylates, polyethyleneterephthalates, bisphenol A (a common environmental contaminant), ethyl cellulose, nitrocellulose, polyurethane, and nylon. Specific exemplary biological matter includes cancer cells, including distinguishing between metastatic and normal cancer cells; proteins, nucleic acids, antibodies, or the like. 
     As used herein, the terms “adapted for communication”, “communicating,” or similar terms refer to any means, structures, or methods for establishing fluid flow through the system, as are well known by practitioners in the art. Exemplary structures are shown in the Figures. For example, a conduit may have a connector adapted to receive or connect to a mated connector on another conduit. As used herein, the term “connector” refers to any structure used to form a joint or to join itself to another piece. These connectors or connections establish a fluid flow path through various elements of the apparatus, assembly, or system. Typical connections include but are not limited to mating connections, such as Luer-type, screw-type, friction-type, or connectors that are bonded together. 
     As used herein, “adapted for engaging”, “engagement”, “engaging”, or similar terms refers to complementary structures that may align, mesh, mate, or rest near, against, or within each other. Exemplary structures include the connectors described above. 
     A device  10 , according to an exemplary embodiment of the present invention that is shown in FIG. 1, includes a specimen container  20  holding a fluid specimen  23 , a particulate matter separation chamber  30  having a porous filter arrangement, and a pump  40 . FIG. 1 also shows a hollow tube  50  that includes a dispersing element  51 . 
     Each of these elements will now be described in more detail. 
     THE COLLECTION CONTAINER 
     In accordance with the invention, specimen container  20  includes any container suitable for holding a fluid  23 , preferably a biological fluid. The typical container includes sidewalls  21  and a bottom wall  22  that, in combination, contain the specimen  23 . The specimen container  20  also has an open end  24  for collecting, holding, or storing the fluid  23 . Typical fluids include, but are not limited to biological fluids, such as body fluids, wastewater fluids, or the like. Typical body fluids include urine or other biological fluids, such as blood, cerebrospinal fluid (CSF), bronchial lavage, sputum or fine needle aspirates. 
     The configuration and materials used to make the container (and any of the elements that comprise a device according to the invention) can be any of a variety of materials, shapes, and sizes. For example, the cup can be constructed of any material compatible with the fluid to be processed. It will be appreciated that the container and the assembly of the sidewalls to the bottom wall can be any conventional assembly. In a preferred embodiment of the invention, bottom wall  22  is a conical member, as shown in FIG.  1 . Optionally, bottom wall  22  or sidewall  21  may include one or more fins or the like (not shown) extending into the interior of container  20 . Such fins may be desirable an embodiment of the invention described in more detail below in which the sample in the container is agitated by rotation of the container. 
     As shown in FIGS. 1 and 2, a device according to the invention also includes a cap  31 . In a preferred embodiment of the invention, the cap  31  is configured or adapted to receive a lower portion  32  of a particulate matter separation chamber  30 . The cap  31  may be variously configured to achieve the desired function. A preferred embodiment is shown in FIG.  2 . The cap  31  may include a downwardly extending member  51  configured to engage sidewall  21  of container  20 . It is intended that cap  31  may be any configuration or shape that closes or seals open end  24  of container  20 . 
     The cap also includes portion  52  having an opening  53  adapted to receive the lower portion  32  of the particulate matter separation chamber  30 . Although the engagement between cap portion  52  and lower portion  32  may be variously configured, lower portion  32  preferably includes a groove  53  adapted to receive a projection  54  from cap portion  52 . In a most preferred embodiment of the invention, the engagement is a snap fit, with the engagement between lower portion  32  and the projection  54  permitting lower portion  32  to rotate relative to cap portion  52 . This configuration is preferably liquid tight, and in a most preferred embodiment of the invention, the seal is liquid tight, but not gas (e.g., air) tight. 
     A preferred configuration for the cap  31  will now be described with respect to FIG.  13 . The cap  31  may be variously configured to achieve the desired function. According to this embodiment of the invention, cap  31  includes structures and means for allowing an outer cap  71  to move in relation to an inner cap  72 . Outer cap  71  is preferably fixed to and/or in fluid communication with tube  50 . In a preferred embodiment of the invention, the outer cap  71  and tube  50  are relatively rotatable with respect to inner cap  72 , when inner cap  72  is tightened on container  23 . Such relative motion between outer cap  71  and inner cap  72  moves sample in the container  23  in relation to agitator  58 A (FIG.  1 ), brush  58 B (FIG. 10) or broom  58 C (FIG.  11 ). 
     In the embodiment of the invention that includes the inner and outer caps, it is preferred that the inner and outer caps are adapted to engage each other so that the respective caps do not rotate until the final closing of the cap on the container. It is intended that at least initially, the respective caps act as a unitary cap. When the cap unit is tightened to a pre-determined position, however, it is intended that any structures holding inner cap  72  in place in relation to the outer cap  71  be broken or released so that inner and outer caps rotate freely with respect to one another. For example, inner cap  72  may be used to seal the container and outer cap  71  may snap fit over the inner cap  72 . In this embodiment of the invention, a tab or the like on the inside of the outer cap  71  may prevent relative movement between the inner and outer caps when the respective caps are in a first position. Moving the outer cap  71  to a second position, e.g., breaking the tab, permits rotation of the outer cap  71  relative to the inner cap  72 . Alternatively, it is envisioned that a temporary spacer (not shown) would initially maintain the inner and outer caps at an axially spaced apart position. After tightening the inner cap  72  on to container  20 , the spacer would be removed and the outer cap  71  slid axially over the inner cap  72  to a position that is freely rotatable with respect to the inner cap  72 . 
     An alternative or additional structure in the embodiment of the invention that includes a cover with a flexible wall  55 , preferably circular or elliptical, that engages and or supports a portion  45  of the particulate matter separation chamber  30 . In a most preferred embodiment of the invention, the wall  55  includes one or more spaced apart notches (not shown). It is intended that these notches provide a degree of flexibility in the wall so that, if desired, the lower portion of the particulate matter separation chamber  30  can be disengaged from the cap  31  (see, for example, FIG.  5 ). 
     FIG. 5 also illustrates another embodiment of the invention relating to a cap  31  having a slot through which the agitator  58 A or broom  58 C can be positioned inside the container  20 . In a preferred embodiment of the invention, the slot or opening in the cap  31  can be covered with a removable and/or penetrable covering that protects the inside of the container  20  from contamination until the container  20  is ready for use. For example, a brush  58 B or the like can be used to collect a cervical sample, the covering can then be removed from the cover  31 , and the brush  58 B can be placed in the container  20 . 
     According to another preferred arrangement, the inner cap  71  may have a collar (not shown) that coaxially circumscribes tube  50  and extends partially into the container  20 . Such a collar redirects the specimen  23  back down into the container  20  during agitation, such as would occur during vortex agitation. This is advantageous insofar as the collar imposes little or no resistance to relative rotation between the inner cap  71  and the outer cap  72 . Moreover, it is envisioned that the outer cap  72  may have formed thereon a mating nipple for attaching the tube  50 . The mating nipple may be formed on the outer cap  72  so as to extend coaxially within the collar. In this way, a telescoping or breakable tube  50  may be used in its elongated configuration to collect the specimen, and then reconfigured to its collapsed configuration and attached to the mating nipple. Such an arrangement according to this embodiment would further reduce the possibility of sample contamination by minimizing handling of the specimen between the time the sample is collected and the time it is examined. 
     PARTICULATE MATTER SEPARATION HOUSING 
     In accordance with the present invention, a device according to the invention includes a particulate matter separation housing that may be variously configured. An exemplary configuration is shown in FIG.  2 . Any housing  30  adapted to receive a particulate matter collection assembly  33  may be used. 
     As shown in FIGS. 1 and 2 the particulate matter separation chamber  30  is preferably a two piece housing formed by a top portion  41  and base portion  32 . In a preferred embodiment of the invention, top portion  41  releasably engages base portion  32 ; however, alternative chamber configurations or assemblies that providing access to the porous filter arrangement  35  are suitable. In a preferred embodiment of the invention, base portion  32  includes a side wall  47 , typically circular, that optionally includes a serrated portion  63  (shown in FIG. 4A) that engages or communicates with side wall  44  and seat  42  of top portion  41 . It has been found that the optional serrated portion  63  of the lower portion  32  facilitates disengaging the lower portion  32  from the top portion  41 . Top portion  41  and base portion  32  may be connected or fastened to each other by any mating connection or means that provides a liquid or fluid tight fit, e.g., Luer-type (threaded or not threaded), screw thread-type, friction-type, a tapered mating connection, or snap fit (as illustrated). 
     Base portion  32  includes a side wall and bottom wall suitable for seating a particulate matter filter assembly  33 . Base portion  32  may also include a central bore or aperture  34  communicating with the hollow tube  50 . In a preferred embodiment of the invention, hollow tube  50  extends into specimen container  20 . In a preferred embodiment of the invention, base portion  32  may be a separate structure that is capable of rotating with respect to the cap  31 . In order to achieve ease of centrifugal rotation while maintaining a liquid-tight assembly, base portion  32  may matingly engage base  31  through a tongue and groove arrangement (see FIG.  2 ). 
     In accordance with an embodiment of the invention, base portion  32  of the particulate matter separation chamber  30  housing includes a bottom wall or seat  39 . As shown in FIGS. 4A-4C, seat  39  may include one or more spaced apart ribs or projections  60 . Projections  60  are preferably of a configuration, size, and shape sufficient to prevent porous arrangement  35  flush contact with seat  39 . In the embodiment shown in FIG. 4A, projections  60  are concentric rings. 
     Alternative configurations are described in more detail below. In a preferred embodiment of the invention, projections  60  function in one or more of the following ways: projections  60  may break the surface tension between porous filter arrangement  35  and seat  39  during use; when porous filter arrangement  35  is to be pulled away from seat  39 , first porous medium  36  does not remain in contact with seat  39 ; projections  60  may evenly distribute pressure of the porous filter arrangement in the particulate matter separation chamber  30 ; projections  60  may prevent or suppress compression of the porous filter arrangement; and projections  60  may be configured to distribute any collected particulate matter in a pre-determined configuration or spatial distribution. 
     In accordance with the present invention, the surface of seat  39  may include one or more structures, configurations, or surface textures that promote the ability of the porous filter arrangement  35  to release from the seat  39 , that promote a pre-determined spatial distribution of particulate matter on the collection site, and/or prevent or suppress compression of the porous filter arrangement  35 . One embodiment of the invention includes concentric projections, such as projections  60  described above. Other configurations include, but are not limited to a grid, cross-hatching or the like, concentric squares or rectangles, or a series of continuous or separated structures, nubs, protuberances, granulations, or the like (see FIGS.  4 B and  4 C). It is intended that any element, structure, or chemistry that provides a texture to the surface of the seat  39  for accomplishing the above stated functions is suitable for use with the present invention. 
     In a preferred embodiment of the invention, the surface of the seat is configured into cross-hatching (see FIG.  4 C). In another preferred embodiment of the invention, the surface of the seat is configured into a sundial or clock face structure (see FIG.  4 B). Both of these embodiments, as well as other surface configurations disclosed herein, promote the collection of particulate matter on the collection site in a pre-determined spatial arrangement. The configurations shown in FIGS. 4B and 4C are particularly desirable because the imprint of the surface treatment of the seat may be transferred to the microscope slide and used to locate and identify specific particulate matter, such as a cancer cell, using a coordinate system. It has been found that a greater portion of particulate matter collects in regions on the collection site corresponding to or opposite areas  75  of the seat. Conversely, high spots  76  are regions that correspond to areas of where smaller amounts of particulate matter collects on the collection surface. These regions are imprinted on the microscope slide when the collection surface is placed in contact with the slide. 
     For example, a technician reading a microscope slide according to the present invention may be able to identify and locate a cell of interest by noting that the particular cell can be found at an angular position corresponding to 2 O&#39;clock on the clock face configuration shown in FIG.  4 B. Imprinting a microscope slide in such a manner significantly speeds reviewing slides and significantly improves the ability of a technician to find previously identified matter of interest. Included with the invention are one or more structures on the seat surface that provide positive orientation of the particulate matter as it is collected on the collection site and transferred to the microscope slide. For example, a suitable coordinate-identifying structure may be an arrow  71  or the like, as shown in FIG.  4 B. 
     In accordance with another embodiment of the invention, the seat  39  and/or lower portion  32  may optionally include a channel  70  or the like, examples of which are shown in FIGS. 4B,  4 C and  7 - 9 . In a preferred embodiment of the invention, seat  39  slopes slightly outward toward the channel  70 . The slight slope of the seat  39  and the channel  70  promote enhanced fluid flow through the particulate matter separation chamber  30  and decreases the surface tension of the seat  39  on the filter arrangement  35 , both of which promote the capability of the porous filter arrangement  35  to disengage from the lower portion  32  of the particulate matter separation chamber  30 . This aspect of the invention is another structure(s) that promote release of the porous arrangement. 
     Additional structures are shown in FIGS. 7-9 that address or are involved with promoting fluid flow through the particulate matter separation chamber  30  and also are involved in the release of the porous filter arrangement  35  from the lower portion  32 . FIG. 7 shows flap  72  that extends downwardly into channel  70  from the lip of seat  39 . FIG. 8 shows an O-ring  73  or the like that is positioned in the channel  70 , preferably so that a top surface of the O-ring  73  is slightly above the plane of seat  39 . This insures that O-ring  73  will engage a portion of porous filter arrangement  35  when positioned in the lower portion  32 . FIG. 9 shows a flap  74  that extends upwardly from an outer portion of seat  39 , insuring that flap  74  will engage a portion of porous filter arrangement  35  when positioned in the lower portion  32 . In a preferred embodiment of the invention, flap  72 , O-ring  73 , and flap  74  are made of a resilient material. The preferred configuration is that shown in FIG.  9 . 
     In accordance with the invention, the particulate matter separation chamber  30  is configured to receive a porous arrangement  35  having a particulate matter collection site  36  adapted to collect particulate matter as fluid containing the particulate matter passes through the chamber  30 . 
     Porous arrangement  35  having a collection site  36  adapted to collect matter may be positioned across a fluid flow path, the collection site  36  communicating with hollow tube  50 . The porous arrangement  35  within the matter separation chamber is preferably adapted to define at least one fluid flow path having first and second branches, the first branch  61  extending through the collection site  36  and the second branch  62  bypassing the collection site  36  (e.g., see FIG.  3 ). 
     In a preferred embodiment, the invention includes a porous filter arrangement  35  having a first porous medium  37 , suitable for preventing the passage of particulate matter therethrough, and a second porous medium  38 , suitable for allowing fluid to pass therethrough. The second porous medium  38  may or may not be capable of removing particulate matter from the fluid  23 , a design choice according to the needs of a particular device. In a preferred embodiment, the first porous medium  37  is suitable for capturing or collecting particulate matter, and even more preferably, capturing or collecting particulate matter in a uniform or single layer. A preferred embodiment also includes a second porous medium  38  that is suitable as a support for the first porous medium  37 . 
     The nature of the material used to make the porous media, the compatibility of the materials chosen for the porous media with one another and with the liquid to be processed are all factors to be considered in selecting a particular material for a porous medium for a given application. 
     Porous filter arrangement  35  may include a unitary structure having a first porous medium  37  of density and/or pore size suitable to prevent the passage of cells therethrough and a second porous medium  38  of density and/or pore size suitable for passing the fluid therethrough. 
     In a preferred embodiment, the porous filter arrangement  35  includes a first porous medium  37  comprising a porous polycarbonate membrane, suitable for preventing the passage of particulate matter therethrough. The porous filter arrangement  37  may further include second porous medium  38  comprising a depth filter or frit. The depth filter may be made of polypropylene or high-density polyethylene POREX® porous plastics. In a preferred embodiment of the invention, the second porous medium  38  may include a serrated or saw-tooth downstream portion  64 , an example of which is illustrated in FIG.  2 . It is intended that portion  64  is a structure and configuration that reduces or ameliorates compression of the porous filter arrangement  35  when it is positioned in the particulate matter separation housing  30 . 
     It should be noted that various types of porous filter arrangements  35  could be used interchangeably with that of the present embodiment. While a polycarbonate membrane  37  is especially suitable for use in the cytology collection apparatus of the present invention, other porous membranes are also suitable. Exemplary porous membranes are disclosed in U.S. Pat. Nos. 5,471,994 and 5,301,685, which are incorporated by reference. 
     The porous membrane  37  preferably has a pore size from about 0.22 microns to about 8 microns, more preferably from about 1 micron to about 6 microns, most preferably about 2 microns, which allows it to trap particulate matter, e.g., cells, which are more than 3 microns in size. The membrane is suitable to allow fluid flow to pass therethrough while preventing the passage of particulate matter. The second porous medium  38  is suitable for passing fluid therethrough and may also be capable of removing particulate matter from the fluid  23 . The pore size of the second porous medium  38  may range from about 5 microns to about 60 microns, preferably from about 15 microns to about 45 microns, most preferably about 35 microns. 
     As one skilled in the art will recognize, adjusting the pore size of the porous membrane  37  and the porous depth filter  38  in accordance with the type and/or size of matter to be collected permits the collection of the particulate matter on the collection site. In a preferred embodiment of the invention, the pore size is chosen so that a uniform layer of matter, preferably a monolayer of matter, is formed on the collection site. For example, from about 3μm to about 40μm or more has been shown to be effective, but it is intended that the invention should not be limited to a certain range of pore size. 
     In a most preferred embodiment of the invention, first porous medium  37  is attached to second porous medium  38  using an adhesive that is soluble in liquid. Such soluble adhesives include but are not limited to sugar compositions, gels, and the like. 
     The first porous medium  37  and the second porous medium  38  may be positioned in any fashion that functions as described herein. As one skilled in the art will recognize, the porous filter arrangement  35  may be variously configured and positioned as needed to achieve a particular result. For example, the first and second porous media may be separate, spaced apart media; the two media can be laminated together; the first medium can be integral with or removably engaged with the second porous medium; or the collection element may comprise a zone of higher density which mimics the function of the first porous medium as described above, and zone of lower density which mimics the function of the second porous medium as described above. Choice of these various configurations are well within the skill of practitioners in the art. Variations on the structure and composition of the porous arrangement will be described in more detail below. 
     As shown in FIG. 12, a porous support  38  with at least one through bore  73 , preferably a bore positioned near the circumference of the porous support  38 , provides a direct conduit for suction so that a filter membrane  37  is retained on the porous support  38  when the particulate matter separation chamber  30  is opened to expose the membrane  37  for further processing. 
     In another embodiment of the invention, lower portion  32 , tube  50 , and fins  58  form an integral unit, and may be separated from cap  31  to facilitate removal of the integral structure from container  20 . An exemplary structure of this embodiment of the invention is shown in FIG.  5 . 
     PUMP 
     In accordance with the invention, specimen container  10  includes a pump  40 . In a preferred embodiment of the invention, pump  40  is a syringe or the like for altering differential pressure within the apparatus so that fluid can be drawn from the specimen container  20  through the particulate matter separation chamber  30 . 
     In accordance with the present invention, the pump  40  may be variously configured. In a preferred embodiment of the invention, pump  40  includes an end that forms the cover portion  41  of the particulate matter separation chamber  30 . Cover portion  41  includes a seat  42  or the like configured to engage a downstream portion of porous filter arrangement  35 . In a preferred embodiment of the invention, the seat  42  positions porous filter arrangement  35  in the cover so that porous filter arrangement  35  does not move during use. In a most preferred embodiment of the invention, seat  42  includes a plurality of projections or posts  43  of a size, shape, and number to position the porous filter arrangement  35  in the particulate matter separation chamber  30 , to promote substantially even distribution of pressure against the porous filter arrangement  35 , and to reduce or prevent compression of the porous filter arrangement  35  that could interfere with fluid flow through the porous filter arrangement  35 . 
     In a preferred embodiment of the invention, cover portion  41  removably engages bottom portion  32  to form the particulate matter separation chamber  30 . Cover portion  41  may engage bottom portion  32  in any manner and with any structures that allow cover portion  41  to disengage bottom portion  32 . In a preferred embodiment of the invention, illustrated in FIG. 2, cover portion  41  includes a downwardly extending side wall  44  having a flange  45  or the like adapted to releasably and/or resiliently engage a shoulder  46  or the like on bottom portion  32 . 
     Movement of fluid through the collection apparatus may be effected by maintaining a pressure differential between a source of fluid and the destination of the fluid. Exemplary means of establishing this pressure differential may be by applying pressure to any part of the system on the inlet side of the particulate matter separation chamber  30  (e.g., the specimen container  20 ); applying a vacuum to any part of the system on the outlet side of the housing (e.g., the syringe  40 ); or any form of pump, such as an autovial spunglass filter (manufactured by Genex Corporation); gravity head; or a flexible, collapsible container, such as a specimen container, which may be squeezed to force fluid through the matter collection apparatus and into the syringe. In a preferred embodiment of the invention, a syringe draws fluid from a collection cup through the housing. 
     HOLLOW TUBE 
     In accordance with a preferred embodiment of the present invention, specimen container  20  includes a tube  50  or the like for drawing fluid  23  into the particulate matter separation chamber  30 . Typically, tube  50  will be hollow and open or openable at both ends. Tube  50  includes open end  51  near the bottom of the collection chamber  23 , and may include one or more apertures  52  into tube  50 . Open end  51  and/or apertures  52  permit different fluid layers as well as sediments to be simultaneously tested when the fluid is drawn into the particulate matter separation chamber  30 . 
     In accordance with another embodiment of the improved invention, hollow tube  50  includes at least one projection or fin  58 A or the like, as shown in FIG.  1 . In a preferred embodiment of the invention, hollow tube  50  is rotatable and fin  58 A stirs the liquid specimen, and in a most preferred embodiment, disperse cells and/or particulate matter, and/or to disrupt any large particulate matter such as mucoid bodies. In another preferred embodiment of the invention, hollow tube  50  and lower portion  32  are of unitary construction, and the lower portion  32 , tube  50 , and fin  58 A are movable in relation to the specimen container  20 . For example, if the container is rotated, optional fins in the side and/or bottom walls of the container may create concentric movement of the sample in the container, movement that will be disrupted by the presence of fin  58 A. Alternatively, lower portion  32 , tube  50 , and fin  58 A may be rotated within a stationary container. 
     As shown in FIGS. 10 and 11, as an alternative embodiment of the invention, agitator  58  may comprise fibers, a brush, swab, or broom or the like. Preferably, such fibers or brush are suitable for dispersing particulate matter in the container when the sample is vortexed in relation to the agitator, brush, or broom. In a most preferred embodiment of the invention, the brush or broom is also suitable for use in collecting particulate matter from a patient, e.g., a cervical brush or broom or the like. It is intended that the brush can be fixed to a portion of the cap  31 , or the cap  31  may include a slot, collar or the like for matingly engaging a portion of the handle at the opposite end of the brush. 
     MIXER 
     FIGS. 13-15 show an apparatus for a semi-automated method according to a first preferred embodiment of the invention. In particular, FIGS. 13-15 show a most preferred embodiment comprising a support sleeve A for positioning and rotating the container and the inner cap  72 . In the most preferred embodiment of the invention, the outer cap  71  is engaged by one or more resilient bands B that in a loosened or first position (FIG. 14) do not engage outer cap  71 , and in a tightened or second position (FIG. 15) engage and hold the outer cap  71  while the inner cap  72  and container  20  are rotating. In an alternative embodiment, belt B may be a drive belt that rotates the outer cap  71 , tube  50  and agitator  58 , as a unit, with respect to container  20  and inner cap  72 . 
     In accordance with a second preferred embodiment of the invention, the specimen collection and processing assembly  10  may be adapted for use with a processing apparatus shown generally as  100  in FIG.  16 . Processing apparatus  100  includes a lower platform  101  having at least one, and preferably a plurality of, sockets  102  adapted to receive a bottom portion of specimen container  20 . Specimen container  20  may fit snugly in socket  102 , or socket  102  may include any of a variety of resilient members that position and hold the specimen container in place. An exemplary resilient member includes an O-ring or a rubber gasket. 
     Processing apparatus  100  also includes an upper platform  103  adapted to receive a top portion of pump  40 , preferably a top portion of plunger  104 . In a most preferred embodiment of the invention, upper platform  103  includes a recess, slot, notch, or opening adapted to receive the top portion of plunger  104 . 
     Upper platform  103  is supported by moveable base  105 , typically a cylinder or the like, that can be raised and lowered in relation to platform  101 . Movement of upper platform  103  raises or lowers plunger  104  in relation to pump  40 . 
     Lower platform  101  rests on or forms a portion of housing  106 . Housing  106  encloses a centrally located drive or sun gear  120 . Drive gear  120  is adapted to engage a plurality of planet gears  121  adapted to communicate with or corresponding to socket  102  or container  20 . In a preferred embodiment of the invention, rotational movement of the sun gear turns each of the planet gears, which in turn rotate container  20  in relation to fin  53 . Alternatively, planet gear  121  may include an element that engages and rotates fin  53 . 
     In operation, a technician places or collects a liquid sample in container  20  and closes the container with a cover  31 /pump  40  assembly. A bottom portion of container  20  is then positioned in socket  102  and a top portion of plunger  104  is positioned in a slot in upper platform  103 . The technician may then activate a motor or the like that rotates sun gear  120 , which in turn rotates planet gears  121 , which in turn rotate container  20  around an axis. When mixing is complete, upper platform  103  is raised, drawing plunger  104  out of the pump body. Movement of the plunger draws sample in the container  20  through the particulate matter separation housing and through the porous arrangement and into the chamber in pump  40 . Each of these steps may be repeated as often as desirable. 
     KIT 
     The present invention is also directed to a particulate matter collection and testing kit containing the collection apparatus  10  as an integral unit. The kit may include at least one specimen container  20 , at least one particulate matter separation chamber  30 , at least one pump  40 , and at least one porous filter arrangement  35 . A kit according to the invention may also include replacement filters, replacement disposables, and/or other components or solutions typically used during particulate matter testing or examination procedures, e.g., cytological examinations. 
     METHOD 
     The present invention also includes a method for removing particulate matter from a fluid, and for transferring particulate matter, such as cells, to a microscope slide. In contrast to currently available methods, the use of membrane filtration provides a method of depositing cells evenly over a microscope slide with minimal overlap. This allows for clear observation and optimal diagnostic accuracy. 
     A method includes collecting a fluid sample containing particulate matter in a collection container  20 . The container  20  is then capped with an assembly that includes one or more of the following: cap  31 , particulate matter separation chamber  30 , and pump  40 . Pump  40  is then activated to pull fluid from container  20  through particulate matter separation chamber  30  into pump  40 , e.g., by withdrawing the piston in a syringe. 
     When the fluid is pulled from the container  20  to the pump  40 , fluid will flow through porous filter arrangement  35  as shown in FIG. 3, so that a monolayer of particulate matter is formed on collection site  37 . Once the monolayer of cells is formed, fluid flow is reduced in the center of porous filter arrangement  35  and increases towards the edges of the porous filter arrangement  35 . This may be due to the blockage of fluid flow by the collected cells as they form the monolayer on the surface of the porous filter arrangement  35 . When the monolayer has mostly covered the surface  45  of the porous arrangement, the flow of fluid bypasses the first porous medium  37  and passes through the extended side area of the second porous medium  38 . Thus, the area of the second porous medium  38  extending beyond an end wall or skirt of the top portion acts as a vent (with low resistance to flow) that prevents cells piling up or collecting in more than a monolayer. Fluid may be passed back and forth through the porous arrangement as many times as desirable. 
     Pump  40  may then be disconnected from base  31 , and thereby exposing porous filter arrangement  35 . Once porous filter arrangement  35  is removed from lower portion  32 , easy access is gained to first porous medium  37 . Alternatively, disengaging top portion  41  of pump  40  from lower portion  32  may also remove porous arrangement  35  from well  32 . 
     The first porous medium  37  may then be pressed against a microscope slide to allowing particulate matter collected on the collection site to be transferred, as they were collected, onto the slide. This allows a cytological examination to be performed on the cells by the practitioner without the interference of the pores in the membrane or delay due to processing requirements. 
     Since cellular detail is dependent on fixation, it is preferred that cells be fixed immediately after being deposited on the slide. Too long a delay between preparation and fixation may expose the cells to drying, which may be detrimental to the cellular structure. Moreover, air-drying artifacts can adversely affect the subsequent staining results. An exception is when the cells are stained with Wright-Giemsa, where air-drying is used as the fixation step. 
     In an another embodiment of the present invention, the monolayer of cells may be fixed directly on the collection site. This may be carried out by first depositing a monolayer of cells on the collection site of the cytology collection apparatus as described above and subsequently passing a solution containing a fixative, such as alcohol or acetone, through the cytology collection apparatus. 
     ALTERNATIVE CONFIGURATIONS 
     The matter collection apparatus or module described above may be used in combination with other suitable filtration or treatment devices. Exemplary devices include other debris and/or assay devices or modules that may be attached to housing  10 . Typically, these additional modules will include a housing having an inlet and an outlet, and will include a filtration, assay, or detection element positioned across the fluid flow path in the housing. For example, the apparatus may comprise a housing including inlet and outlet ports defining a flow path between the inlet and the outlet; a filter positioned across the flow path; and a freely movable chromatography/assay element, such as substrate beads, positioned on the outlet side of the filter. The chromatography/assay element can freely mix with the matter in the fluid, capture the matter, and can then be assayed for the presence of the matter. Suitable devices include those disclosed in U.S. Pat. Nos. 4,953,561; 5,224,489; 5,016,644; 5,139,031; 5,301,685; 5,042,502 and 5,137,031, which are incorporated by reference. 
     Included within the scope of the present invention is producing a single slide from a patient sample, producing multiple slides from a single patient sample, or producing multiple slides from multiple patient samples. It is intended that a patient sample may be processed in a single shot, batch, or continuous manner. Additional slides for other stain applications can be easily prepared. Human papilloma virus testing, for example, by newer methods such as immunocytochemistry or in-situ hybridization can be performed on the additional slides. As oncogene products or other immunocytochemical tests are developed, more slides may be necessary. The different fixations that these tests may need can easily be incorporated into the procedure since the preparation does not require the slides to be fixed in only one way. 
     The most widely used stain for visualization of cellular changes in cytology is the Papanicolaou staining procedure. This stain, which is used for both gynecologic and nongynecologic applications, is basically composed of blue nuclear and orange, red and green cytoplasmic counterstains. The nuclear stain demonstrates the chromatic patterns associated with normal and abnormal cells, while the cytoplasmic stains help to indicate cell origin. The success of this procedure can be attributed to the ability to observe a number of factors, including definition of nuclear detail and cell differentiation. This staining procedure also results in a multicolor preparation that is very pleasing to the eye, possibly reducing eye strain. This same slide preparation procedure can be used for virtually all forms of cytology. 
     Furthermore, the use of completely contained disposable components addresses biohazard concerns. Ultimately, the enhanced presentation of cells, yielding improved cytologic interpretation, may expand the role of cytology by providing more consistent and reliable patient diagnosis. 
     Also, captured microorganisms can be cultured in culture medium. After a monolayer of cells has been collected in the cytology collection apparatus, fluid may be used to back-flush the collection site, thereby transferring any collected microorganisms from the collection site. 
     In bacteria testing, the first porous medium can be used for culturing with a Qualture device (not shown) to determine the presence of specific bacteria colonies. The Qualture device is a plastic capsule containing a filter membrane and four nutrient pads of dehydrated, selective media. 
     The Qualture technique is more sensitive than the agar plate method and more rapid in determining a presumptive diagnosis. The device screens, isolates and presumptively diagnoses bacterial isolates in one step most often in 4-6 hours. Tests have demonstrated that recovery from fifty milliliters of fluid is excellent and sensitive. 
     Although the present invention has been described in terms of a particular preferred embodiments, it is not limited to those embodiments. Alternative embodiments, examples, and modifications that would still be encompassed by the invention may be made by those skilled in the art, particularly in light of the foregoing teachings.