Patent Publication Number: US-2021187417-A1

Title: Method and Apparatus for Processing and Analyzing Particles Extracted From Tangential Filtering

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of U.S. Provisional Application No. 61/911,840, filed Dec. 4, 2013, U.S. Provisional Application No. 62/017,604 filed Jun. 26, 2014, and U.S. Provisional Application No. 62/050,859 filed Sep. 16, 2014. The disclosure of each of these documents is hereby incorporated in its entirety by reference. 
    
    
     BACKGROUND OF THE INVENTION 
     Field of the Invention 
     Mechanical particle filters are used to extract particles for analysis from a fluid/particle mixture. However, now the particles are retained by the filter. The most common technique for removing particles from a filter for analysis is to introduce additional fluid, such as by using a backwashing process. However, ideally, the particles should be contained in the smallest amount of fluid possible while maintaining high retention ratio for ease of analysis. This is especially true when the particles are bacteria. Therefore, while backwashing a filter does remove the particles from the filter, the efficiency of the process is low and the quantity of fluid required may produce a secondary fluid/particle mixture with excessive fluid. 
     Furthermore, when using hydrophilic membrane with small pore size and when suction is provided on the downstream side of the filter to draw fluid and undersized particles, often times, the membrane will become a barrier to air after it was wetted. 
     A design and method are needed, whereby the particles of interest may be filtered and contained within a small volume of fluid and, furthermore, whereby the filter may be constructed such that, even after the fluid passes, the membranes of the filter will allow more suction using vacuum. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is an exploded view of a simplified schematic showing a prior art filter arrangement; 
         FIG. 2  is an assembled view of a schematic of the filter arrangement in  FIG. 1 ; 
         FIG. 3  is a schematic illustrating a perspective arrangement of a prior art the filter arrangement disassembled and without the filter element; 
         FIG. 4  is a schematic of the embodiment of the prior art filter arrangement of  FIG. 3  but with a filter element placed in position; 
         FIGS. 5A-10A  are schematic views of the top half and bottom half of one embodiment of the filter arrangement in accordance with the subject invention illustrating different configurations for the filtering process; 
         FIGS. 5B-10B  are schematics of the filter arrangement in the assembled state showing different configurations for the filtering process; 
         FIG. 11A  is a schematic view of the top half and bottom half of one embodiment of the filter arrangement utilizing check valves and modified channels to provide dual inlets for the elution and water and dual outlets for the vacuum; 
         FIG. 11B  is a schematic view of the filter arrangement in  FIG. 11A  in the assembled state; 
         FIGS. 12A-17A  are schematic views of the top half and bottom half of another embodiment of the filter arrangement illustrating different configurations for the filtering process and, furthermore, utilizing stopcock valves to create different fluid paths; 
         FIGS. 12B-17B  are schematic views of the filter arrangement of the embodiment illustrated in  FIGS. 12A-17A  in the assembled state showing different configurations for the filtering process; 
         FIG. 18A  is a schematic view of a filter arrangement utilizing a sandwiching arrangement, whereby a previously described “top portion” is sandwiched between two “bottom portions” to provide greater filtering capacity; and 
         FIG. 18B  is a schematic view of the filter arrangement in  FIG. 18A  in the assembled state. 
         FIG. 19  is a perspective view of yet another embodiment of the filter arrangement utilizing a slider valve to configure different fluid paths; 
         FIG. 20  is a section view of the valve arrangement showing the slider valve; 
         FIG. 21  illustrates details of the slider valve; 
         FIGS. 22-28  are schematic views of yet another embodiment of the filter arrangement illustrating different configurations for the filtering process and, furthermore, utilizing a slider valve configure different fluid paths; 
         FIGS. 22A, 23A, 25A, 26A, and 28A  are process flow diagrams showing the system in which the filter arrangements, also referred to as filter cartridges, are utilized for the cartridge configurations shown in  FIGS. 22-28 ; 
         FIG. 29  is a process flow diagram showing a system utilizing four separate filter cartridges; 
         FIG. 30  is a partial cross-section side view of a mass meter illustrated schematically in  FIG. 2 ; 
         FIG. 31  is a schematic section view along arrows  29 , in  FIG. 22   
         FIG. 32  is a process diagram generally illustrating the processing of and the identification of cells within a sample; 
         FIG. 33A  illustrates bacteria from a urine specimen plated on blood agar using the WASP system without the concentrating process described herein; 
         FIG. 33B  illustrates bacteria from the same urine specimen plated on blood agar using the WASP system but using the concentrating process described herein; 
         FIG. 33C  illustrates bacteria from a urine specimen plated on Chromagar using the WASP system without the concentrating process described herein; 
         FIG. 33D  illustrates bacteria from the same urine specimen plated on Chromagar using the WASP system but using the concentrating process described herein; 
         FIG. 34  illustrates two separate sets of a urine specimen, one set plated on blood agar and another set plated on Chromagar before and after processing, each using the WASP system; 
         FIG. 35  is an image of two sets of a clinical urine specimen on slides before and after the concentrating process showing the effectiveness of the process in removing proteins, cells and material not of interest; 
         FIG. 36  is an image of two sets of CU specimens on slides before and after the concentrating process showing the effectiveness of the process in removing proteins, cells and material not of interest; and 
         FIG. 37  is an image of two sets of CU specimens on slides before and after the concentrating process showing the effectiveness of the process in removing proteins, cells and material not of interest. 
     
    
    
     DESCRIPTION OF THE INVENTION 
     For purposes of the description hereinafter, the terms “end”, “upper”, “lower”, “right”, “left”, “vertical”, “horizontal”, “top”, “bottom”, “lateral”, “longitudinal” and derivatives thereof shall relate to the invention as it is oriented in the drawing figures. However, it is to be understood that the invention may assume various alternative variations and step sequences, except where expressly specified to the contrary. It is also to be understood that the specific devices and processes illustrated in the attached drawings, and described in the following specification, are simply exemplary embodiments of the invention. Hence, specific dimensions and other physical characteristics related to the embodiments disclosed herein are not to be considered as limiting. 
       FIG. 1  illustrates a prior art filter arrangement  10  having a top element  15 , a bottom element  20 , and a filter element  25  therebetween.  FIG. 1  is an exploded schematic view, while  FIG. 2  is an assembled schematic view of the same parts but with the top element  15  and the bottom element  20  drawn together to compress the filter element  25  therebetween. As an overview, directing attention to  FIG. 2 , a fluid/particle mixture is introduced through inlet/outlet  30  into channels (not shown) extending through the top element  15 . Inlet  35  is closed and a suction outlet  40  provides a vacuum drawing the fluid/particle mixture through the filter element  25 , such that oversized particles remain on the upper surface  45  of the filter element  25 . Thereafter, the inlet  35  is open and the suction outlet  40  is closed. An elution fluid is then introduced into the inlet  35  to tangentially rinse the upper surface  45  of the filter element  25 . This provides a reduced volume fluid/particle mixture that exits the inlet/outlet  30 . As an intermediate step, it is possible to close the inlet  35  and to introduce a water/rinse into the inlet/outlet  30 , while suction outlet  40  is open, to wash over the particles after the initial filtering step to further filter any remaining particles that were not previously washed through the filter. This water/rinse and undersized particle solution are removed through the suction outlet  40  and discarded. As a result, the oversized particles that were deposited upon the upper surface  45  of the filter element  25  are isolated and collected using a reduced volume elution fluid. 
       FIGS. 3 and 4  illustrate a prior art embodiment of the filter arrangement  10  having a top element  20  and a bottom element  15  with a filter element  25  ( FIG. 4 ) therebetween. Each of these figures is illustrated with a filter arrangement  10  in a disassembled state. However, it can be appreciated that the four bolts  26   a ,  26   b ,  26   c ,  26   d  may be secured within the bores  27   a ,  27   b ,  27   c ,  27   d , respectively, with the filter element  25  therebetween to assemble the filter arrangement  10 . The filter arrangement  10  illustrated in  FIGS. 3 and 4 , is a single-stage filter and the suction outlet  35  provides suction to the bottom channel  60 . The top element  20  has an inlet/outlet  40  and an inlet  38 , on the opposite side of inlet/outlet  40 , with a channel  50  therebetween. The filter element  25  is positioned between the top element  20  and the bottom element  15 . In operation, suction is provided at the suction outlet  35  such that there is a vacuum created in the bottom channel  60 . The fluid/particle mixture is introduced through the inlet/outlet  40  of the top element  20  where it travels over the filter element  25  and oversized particles are retained on the upper surface  45  of the filter element  25 . The fluid and undersized particles travel through the filter element  25  into the bottom channel  60  and are removed through the suction outlet  40 . The oversized particles remain on the upper surface  45  of the filter element  25 . Thereafter, suction is discontinued and elution fluid, under pressure, is introduced through the inlet  38  and into the channel  50  where it traverses the upper surface  45  and flushes the oversized particles into the outlet  40  where they are retained in a collector (not shown) for further analysis. The arrangement illustrated in  FIGS. 3 and 4  does not include the intermediate step of rinsing the particles retained on the filter element  25  with water. 
     As known in the prior art, the elution fluid may be effervescent and contain a foaming agent such as TWEEN. The subject filtering arrangement is most effective when the particles are bacteria. The filter element is preferably a polycarbonate-type filter which is a surface filter and may have pores with openings between approximately 0.01 and 50 microns. In one embodiment the openings are preferably approximately 0.4 microns wide. 
     For purposes of discussion, similar elements in different embodiments will be identified with similar numbers but with increments of 100, such as 10, 110, 210. 
     During the discussion of  FIGS. 5A-10A , it should be appreciated that the surfaces illustrated for the top element  115  and the bottom element  120  may be transparent and the top element  115  will be placed over the bottom element  120 , such that the channels in each of these elements  115 ,  120  are generally aligned with one another. Therefore, for purposes of discussion, the top element  115  is transparent and the channels illustrated therein will be on the underside  147  ( FIG. 5B ) of the top element  115 , while the bottom channel  150  illustrated in the bottom element  120  is on the upper surface  152  of the bottom element  120 . The filter element  25  is not illustrated in  FIGS. 5A-10A  but is located between the top portion element  115  and the bottom element  120  as shown in  FIGS. 5B-10B . 
     Valves A-H are illustrated in the top element  115 . Depending upon the configuration of the filter arrangement  110 , one or more of these valves will be open and others will be closed. Such closing will be illustrated by darkening the valve symbol. 
     For the initial configuration, directing attention to  FIGS. 5A and 5B , the fluid/particle mixture is introduced through the inlet  130  and travels through the first-stage channel  160  as indicated by arrow  162 . Valve A is open while valves B, C, and D are closed. In this configuration, a vacuum will be activated such that the suction outlet  140  draws a vacuum through the entire bottom channel  150 . As a result, the fluid/particle mixture is urged against the upper surface  145  of the filter element  125  ( FIG. 5B ), thereby retaining oversized particles  165  on the upper surface  145  of the filter element  125 . Undersized particles, along with fluid, are drawn through the filter element  125  and evacuated along the bottom channel  150  through the suction outlet  140 , as indicated by arrows  67 . At this point, oversized particles  165  and other miscellaneous particles have been deposited upon the upper surface  145  of the filter element  125 . It should be noted that for the arrangement illustrated in  FIGS. 5A and 5B , no more than one-half of the filter element  125  has been utilized. 
     To improve the integrity of the filtering process, the Inventors have learned that additional undersized particles will be washed through the filter element  125  simply by providing a fluid rinse, such as a water rinse, over the particles  165 . 
     Directing attention to  FIGS. 6A and 6B , valves A, B, D, and F are closed and water is introduced through water inlet  170  along the water channel  172 , as illustrated by arrows  174 . Just as with the original fluid/particle mixture, the suction outlet  140  provides a vacuum to the bottom channel  150  such that the water is drawn through the filter element  125  into the bottom channel  150  and follows arrows  176  where it is discharged at the suction outlet  140 . This water rinse removes additional undersized particles that may have been retained during the initial filter step. 
     Direction attention to  FIGS. 7A and 7B , valves A, C, E, and G are now closed and the elution fluid, which will also be referred to as foam, is introduced under pressure at the foam inlet  180  where it travels through the foam channel  182  in a path defined by arrows  184  to a collector  185 , which now contains a reduced volume fluid/particle mixture, wherein the fluid is the elution fluid. It should be noted that the vacuum is off, such that the bottom channel  150  is inactive and the flow of the elution fluid travels across the upper surface  145  of the filter element  125  to deposit the fluid/particle mixture within the collector  185 . This process of passing the fluid across the upper surface  145  of the filter element  125  is known as tangentially rinsing the upper surface  152  and dislodges the particles on the upper surface  145  to mechanically scrape the upper surface  145  and move the particles  165  into the collector  185 . By doing so, the relatively large volume of fluid associated with the initial fluid/particle mixture has been significantly reduced. 
     What has been described so far is a single-stage filtering process that provides a significant reduction in the volume of fluid associated with filtered particles to improve the ease of subsequent examination of the particles. Only a portion of the filter element  125 , which extends essentially across the width of the bottom element  120 , has been utilized. 
     The Inventors have realized that it is possible to provide a dual-stage filter with relative ease to further reduce the volume of fluid in the fluid/particle mixture or to further remove undesired small particles. 
     Directing attention to  FIGS. 8A and 8B , with the refined fluid particle sample in the collector  185 , valves B, C, E, F, and H are closed and suction is introduced to the bottom channel  150  such that fluid from the collector  185  is drawn into the second-stage channel  190  along arrows  191 , where the undersized particles and the fluid are drawn through the filter element  125  into the bottom channel  150  and discharged through the suction outlet  140  along arrows  192 . Additionally, valves A and D are open so that air can come in to permit fluid to be pulled out of reservoir  85 . Once again, particles  165  are deposited upon the upper surface  145  of the filter element  125  but now the elution fluid and undersized particles are passed through the filter element  125  into the bottom channel  150  and out the suction outlet  140 . 
     Directing attention to  FIGS. 9A and 9B , valves C, E, G, and H are closed and water is introduced into the water channel  172  through the water inlet  170  and then into the second-stage channel  190  along arrows  194 . With suction provided in the bottom channel  150 , any undersized particles and the elution fluid remains are again drawn through the filter  125  into the bottom channel  150  where they follow the flow of arrows  196  and are discharged through the suction outlet  140 . 
     Finally, directing attention to  FIGS. 10A and 10B , valves B, G, and F are closed and elution fluid is provided by the foam inlet  180  along the foam channel  182 , as indicated by arrows  198 . Just as before, the elution fluid moves transversely across the upper surface  145  of the filter element  125  and scrapes the particles  165  from the upper surface  145  of the filter element  125 , where they are then transported through the outlet  135  into a secondary collector to provide a fluid/particle mixture, wherein the fluid has an exceptionally low fluid volume relative to the particle concentration, thereby allowing analysis of the particles to proceed with greater ease. 
     Overall,  FIGS. 5-10  illustrate the filter arrangement  110  for isolating particles  165  from a fluid/particle mixture. The filter arrangement is made of a top element  115  having at least one open  60  channel extending thereacross connecting a top element inlet  130  to a first collector  185 , wherein the channel  160  is open on the underside  147  of the top element  115 . A bottom element  120  having at least one open channel  150  extending thereacross connected to a bottom element outlet, or suction outlet  140 . The channel  150  is open on the upper side  152  of the bottom element  120 . The top element  115  is secured to the bottom element  120  such that the underside  147  of the top element  115  is secured against the upper side  152  of the bottom element  120  and wherein the channels  160 ,  150  align with one another. The filter element  125  is generally flat and is positioned between the top element  115  and the bottom element  120  and overlaps with the channels  160 ,  150 . 
     The top element inlet  130  of the filter arrangement  110  is connected to a fluid/particle supply and also top element inlet  180  which is connected to an elution fluid supply, wherein the bottom element outlet  140  is connected to a suction supply. As discussed, the filter arrangement provides a valve arrangement with at least two flow configurations. 
     With suction applied to the bottom element outlet  140 , the fluid/particle mixture is introduced into the top channel  160  and over the filter element  125  thereby depositing retentate particles  165  upon the filter element  125  and passing permeate particles through the filter element  125 . Thereafter, with suction discontinued to the bottom element outlet  140 , the elution fluid is introduced into the top channel  160  and over the filter element  125  such that the retentate particles deposited upon the filter element  125  are tangentially rinsed and collected through the top element outlet  135  into a first collector  185 . 
     A second collector may be positioned within the path of the open channel  160  of the top element  115  to define a first stage channel  160  on one side of the first collector  185  and a second stage channel on the other side of the first collector  185 . The valve arrangement described with respect to the first collector  185  for the first stage channel is repeated for the second stage channel thereby providing a two-stage filter arrangement with retentate initially deposited within the first collector and thereafter finally being deposited within the second collector. 
     Prior to introducing the elution fluid and after introducing the fluid/particle mixture, with suction applied to the bottom element outlet  140 , the rinsing solution is introduced into the top channel  160  and through the filter element  125 . 
     What has so far been described is a filter arrangement utilizing on/off valves A-H to provide different configurations of the subject filter arrangement. In an alternate embodiment, certain of the valves A-H illustrated in  FIGS. 5A-10A  may be replaced with check valves since there is flow in only a single direction through certain valves. By substituting check valves for these on/off valves where possible, the number of controlled elements may be reduced, thereby not only making control of the filter arrangement easier, but such check valves are less expensive than the on/off valves and, as a result, it is possible to fabricate a disposable filter arrangement that will cost less. 
     The reference characters associated with the elements in  FIG. 11A  and  FIG. 11B  are similar to those reference characters found in  FIGS. 5A and 5B , for example, with the exception, however, that each of the valve identifiers, while utilizing the same capital letter, introduces the suffix “1” while the other elements utilize a suffix “A” or, in the event the previous element has now been made into two parts, the suffix “B” will also be used. 
       FIGS. 11A and 11B  include a first bottom channel  150 A and a second bottom channel  150 B as opposed to a single bottom channel  150  illustrated in  FIG. 5A . Additionally, each bottom channel  150 A,  150 B includes a suction outlet  140 A,  140 B to direct fluid in the direction indicated by arrows  167 A,  167 B, respectively. Additionally,  FIG. 11A  includes a first foam inlet  180 A and a second foam inlet  180 B as opposed to a single foam inlet  180 .  FIG. 11A  includes two separate water inlets  170 A,  170 B. By enabling different elution/rinsing fluids within each of the two water inlets  170 A,  170 B and foam inlets  180 A,  180 B, it is possible to enable different elution and rinsing fluids in a first cycle and in a separate second cycle. This will allow buffer exchange between the first cycle and the second cycle. Additionally, through the use of separate suction outlets  140 A,  140 B, it is possible for the second suction outlet  140 B to be used to draw the elution fluid into the second chamber. 
     Directing attention to  FIG. 11A , while valves A 1 -H 1  are illustrated in the top element  115 A, it should be appreciated that valves A 1 -C 1  and E 1 -G 1  are check valves, while valves D 1  and H 1  are on/off valves. For those lines in which flow occurs only in a single direction, the inventor has realized that a single check valve may be substituted for an on/off valve, thereby relieving the operator of the duty of adjusting a valve for operation. 
     As previously discussed with respect to  FIGS. 5A-9A , the filter arrangement  110  may be configured for six separate stages. These stages will hereinafter be referred to as: 1) aspirate sample; 2) first rinse; 3) first extraction; 4) second aspiration; 5) second rinse; and 6) final extraction. 
     For the initial configuration to aspirate the sample, the fluid/particle mixture is introduced through the inlet  130 A and travels through the first stage channel  160 A. Valve D 1  is closed and the vacuum is activated such that the suction outlet  140 A draws a vacuum through the bottom channel  150 A, thereby depositing particles  165 . With particles  165 A deposited upon the upper surface  145 A of the filter  125 A, the first rinse stage begins. Water is introduced at water inlet  170 A through check valve C 1  and into the first stage channel  160 A while the suction provided by the suction outlet  140 A pulls the water/particle mixture through the filter  125 A filtering additional particles that may not have been filtered during the initial step. The vacuum from the suction outlet  140 A is discontinued and the on/off valve D 1  is opened. At this point, elution is introduced under pressure at the foam inlet  180 A where the liquid proceeds past the check valve B 1  into the first stage channel  160 A where it wipes the particles  165  from the top upper surface  145 A of the filter element  125 A into the collector  185 A. 
     Any positive pressure that may be caused by the elution foam breaking down into a liquid may be vented through check valve G 1 . 
     At this point, the second aspiration stage begins with vacuum provided at the suction outlet  140 B and valve H 1  in the closed position. The particle/liquid solution is drawn from the collector  185 A and past valve G 1  into the second stage channel  190 A where it then passes through the filter element  125 A into the bottom channel  150 B where the elution fluid and undersized particles are removed while the oversized particles  165 A remain on the upper surface  145 A of the filter element  125 A. 
     In the second rinse stage, the suction outlet  140 B is still energized but water is now introduced into the second stage channel  190 A through the water inlet  170 B. The water is pulled through the filter  125 A and washes additional particles from the upper surface  145 A of the filter element  125 A through the suction outlet  140 B where it is disposed. 
     The last stage is the final extraction, whereby there is no suction provided through the bottom channel  150 B but elution fluid is introduced through foam inlet  180 B where it travels into the second stage channel  190 A. Valve H 1  is open such that the elution fluid displaces the particles  165 A from the upper surface  145 A of the filter element  125 A and moves them past the open valve H 1  into a final receptacle (not shown). By doing this, particles are provided in a relatively low volume elution fluid which thereafter may be further analyzed with greater ease. 
     The embodiment just discussed in general replaced a number of on/off valves with check valves to make control of the multiple stages of the filter arrangement easier and to reduce costs. 
       FIGS. 12A-17A and 12B-17B  illustrate yet another embodiment, whereby a series of three-way stopcock valves M, N, O, P are utilized to configure the filter arrangement for different stages. Once again, the discussion will be directed to the six stages previously discussed including: 1) aspirate sample; 2) first rinse; 3) first extraction; 4) second aspiration; 5) second rinse; and 6) final extraction. 
       FIGS. 12A and 12B  are directed to the stage of aspirating the sample, wherein the bacteria sample is introduced through inlet  130 C and valves M, N, and O are oriented such that the flow is directed through passageways  210 ,  230 ,  250 , and  290  and into the first stage channel  160 C. Vacuum is applied to the bottom channel  150 C such that particles  165 C are retained on the upper surface  145 C of the filter element  125 C. The liquid and particles that pass through the filter element  125  C are discarded. 
     Directing attention to  FIGS. 13A and 13B , with the particles  165 C retained on the upper surface  145 C of the filter element  125 C, water is introduced by orienting valves M, N, and O such that water enters at the water inlet  170 C and travels through passageways  220 ,  230 ,  250 , and  290  into the first stage channel  160 C. With a vacuum applied in bottom channel  150 C, the water and undersized particles travel through the filter element  125 C and are discarded, thereby providing additional filtering of undersized particles. 
     With particles  165 C deposited upon the upper surface  145 C of the filter element  125 C, those particles may now be extracted. Directing attention to  FIGS. 14A and 14B , elution is introduced through the first stage channel  160 C and valves O and N are oriented such that the flow proceeds through passageways  290 ,  250 , and  240  into the collector  185 C. The elution moves the particles  165 C across the upper surface  145 C of the filter element  125 C and into the passageway  290 . In this manner, a relatively low volume of elution is mixed with the particles  165 C and deposited within the collector  185 C. 
     Any positive pressure that may be caused by the elution foam breaking down into a liquid may be vented through the top of the collector, which is open. 
     The elution/particle mixture now deposited in the collector  185 C may be processed through a second filtering procedure which includes a second stage of aspirating. Directing attention to  FIGS. 15A and 15B , valves N,  0 , and P are oriented such that the elution/particle mixture in the collector  185 C through a vacuum applied to the bottom channel  150 D, is moved through passageways  240 ,  250 ,  270 , and  280  into the second stage channel  160 D and, once again, particles  165 C are deposited on the upper surface  145 C of the filter element  125 C. 
     The second rinse stage, illustrated in  FIGS. 16A and 16B , may now be initiated. In particular, with valves M, N,  0 , and P oriented as illustrated, water may be introduced at the water inlet  170 C such that it travels through passageways  220 ,  230 ,  250 ,  270 , and  280  and into the second stage channel  160 D. There the water and smaller particles pass through the filter element  125 C and are discarded to provide a better sampling of particles  165 C. 
     Now the second stage may be completed with a final extract as indicated in  FIGS. 17A and 17B . In particular, with the particles  165 C deposited upon the upper surface  145 C of the filter element  125 C, elution under pressure is introduced into the second stage channel  160 D, thereby displacing the particles  165 C from the upper surface  145 C. With valve P oriented as shown, the particles and the elution are washed through the second stage channel  160 D into passageway  280  through valve P where they travel through passageway  260  into a final collector (not shown), providing a high quality sample of particles  165 C mixed within a relatively low volume of liquid. 
       FIGS. 12A-17A and 12B-17B  illustrate a filter arrangement having two separate channels  160 C,  160 D each capable of accepting an independent supply of elution and, furthermore, a series of valves M, N,  0 , and P permit the original particle liquid sample to be directed to either the first stage channel  160 C or the second stage channel  160 D. Furthermore, this configuration permits water through inlet  170 C to be introduced into either the first stage channel  160 C or the second stage channel  160 D. 
     Overall,  FIGS. 12A-17A and 12B-17B  illustrate an alternate filter arrangement for isolating particles  165  from a fluid/particle mixture. The filter arrangement is made of a top element having at least one open  160 C channel extending thereacross in fluid communication with a top channel inlet/outlet  162 C to a first collector  185 C wherein the channel  160 C is open on the underside  147 A of the top element  115 . A bottom element  120 A having at least one open channel  150 C extending thereacross connected to a bottom element outlet, or suction outlet,  140 A. The channel  150 C is open on the upper side  152 A of the bottom element  120 A. The top element  115 A is secured to the bottom element  120 A such that the underside  147 A of the top element  115 A is secured against the upper side  152 A of the bottom element  120 A and wherein the channels  160 C,  150 C align with one another. The filter element  125 A is generally flat and is positioned between the top element  115 A and the bottom element  120 A and overlaps with the channels  160 C,  150 C. 
     The top channel inlet/outlet  162 C of channel  160 C of the filter arrangement is connected to a fluid/particle supply and an elution fluid supply, wherein the bottom element outlet  140 A is connected to a suction supply. As discussed, the filter arrangement provides a valve arrangement with at least two flow configurations. 
     With suction applied to the bottom element outlet  140 A, the fluid/particle mixture is introduced through the top channel inlet/outlet  162 C into the top channel  160 C and over the filter element  125 C thereby depositing retentate particles  65 C upon the filter element  125 C and passing permeate particles through the filter element  125 C. Thereafter, with suction discontinued on the bottom element outlet  140 A, the elution fluid is introduced into the top channel  160 C and over the filter element  125 C such that the retentate particles deposited upon the filter element  125 C are tangentially rinsed through the top channel inlet/outlet  162 C and collected into collector  85 C. 
     The top element  115 C may have a second stage channel  160 D extending thereacross in fluid communication with another top channel inlet/outlet  162 D to define a first stage channel  160 C on one side of the top element  115 C and a second stage channel  160 D on the other side of the top element  115 C such that the valve arrangement described in parts 1) and 2) for the first stage channel  160 C is repeated for the second stage channel  160 D thereby providing a two-stage filter arrangement with retentate initially deposited within the collector  185 C and thereafter being processed again and finally being redeposited within the collector  185  C. 
     The top element inlet  170 C may be connected to a rinsing solution supply. Under these circumstances, the valve arrangement may have an additional configuration. 
     In particular, prior to introducing the elution fluid and after introducing the fluid/particle mixture, with suction applied to the bottom element outlet  135 , the rinsing solution is introduced into the top channel  160 D at the top channel inlet/outlet  162 D and through the filter element  125 C. 
     Just as before and as described with respect to the first stage channel  160 C, the second stage channel  160 D may have a similar valve configuration such that the processing of fluid retained in the collector  85 C from the first stage channel  160 C may be introduced into the second stage channel  160 D for further processing and refinement, after which the refined particles are redeposited within the collector  185 C. 
     While predefined steps utilizing this filter arrangement have been described herein, it should be appreciated that depending upon the specific need, there may be a single stage utilized or multiple stages and the individual steps or the sequence of steps may be different. 
     In a further embodiment, a dual filtering arrangement is possible as illustrated in  FIGS. 18A and 18B . In particular,  FIG. 18A  illustrates a top sandwich element  300  identical to the bottom element  120 A illustrated in  FIG. 11A  and illustrates a middle sandwich element  305  similar to the top element  115 A illustrated in  11 B. However, the channels  160 A,  190 A of the middle sandwich element  305  extend completely through the thickness of the middle sandwich element  305 . The channels  60 A,  190 A are in fluid communication with a collector  185 C. Furthermore, a bottom sandwich element  310  is identical to the top sandwich element  300 . However, the channels  350 A,  360 A are on the underside  347  of the top sandwich element  300  while the channels  350 B,  360 B are on the upper side of the bottom sandwich element  310 . 
     As previously discussed, it should be appreciated that the view of the top sandwich element  300  is a transparent view and, in actuality, the channels are on the underside of the top sandwich element  300 . Additionally, the channels in the bottom sandwich element  310  are on the upper side of the bottom sandwich element  310  such that, directing attention to  FIG. 19 , when the top sandwich element  300 , the middle sandwich element  305 , and the bottom sandwich element  310  are placed together, the channels are aligned with one another. Placed between the top sandwich element  300  and the middle sandwich element  305  is a top filter element  315  and placed between the middle sandwich element  305  and the bottom sandwich element  310  is a bottom filter element  320 . By utilizing this configuration, the top filter element  315  and the bottom filter element  320  provide twice the membrane surface with the same channel volume. 
     Any positive pressure that may be caused by the elution foam breaking down into liquid may be vented through the check valve immediately downstream of the collector  185 C. 
     Additionally, the filter elements discussed herein may be made up of a hydrophobic membrane to allow the passage of trapped air to the vacuum side. 
     Finally, a flow sensor may be added to the vacuum side to sense when all of the sample has been aspirated, thereby alleviating the need to have a sensor on the “clean side” of the disposable filter. 
     The method disclosed herein provides for the use of wet foam to remove microorganisms from a membrane surface and resuspend them in a fluid of choice. It is also possible to provide high recovery for low concentration specimens while maintaining consistency regardless of the specimen source. 
     The filter element provides 0.4 micron filtration of permeate and removes proteins, soluble materials and cell fractions. Additionally, by rinsing the filter element with rinsing solution, it is possible to remove small surface hanging particles and droplets from the original matrix while the use of wet foam allows extraction of the microorganisms from the surface of the filter. 
     Through the use of foam, which may be 80-90% gas, during the foam extraction the empty space is filled without contributing to the final sample volume. Additionally, the foam has a higher viscosity which prevents channeling and creates a more uniform flow across the filter surface. The foam produces micro bubbles which behave as deformable solids, effectively squeegeeing the particles off of the surface of the filter element. Overall, the filter based separation of particles in combination with the wet foam extraction into a matrix provides a superior filtering system. 
       FIGS. 19-28  illustrate yet another embodiment similar to that embodiment described with respect to  FIGS. 12-17 , however the stopcock valves M, N, O, P, which were previously utilized to configure the filter arrangement for different stages, has now been replaced with a linear slider valve. Additionally,  FIGS. 22A, 23A, 25A, 26A, and 28A  are process flow diagrams showing the system in which the cartridges are utilized for the cartridge configurations shown in  FIGS. 22-28 . 
     Prior to discussing the individual configurations of a filter arrangement,  FIG. 29  will be reviewed, showing a process flow diagram for an entire cluster of filter arrangements. For convenience, different portions of the process flow diagram are labeled with capital letters PA-PH. 
     Pressurized gas in a pressure vessel PA is introduced to a pressure vessel PB filled with liquid such that the pressurized gas dissolves within the liquid to provide an effervescent liquid. There are two pressurized tanks shown in the process schematic—one with nitrogen and one with carbon dioxide. Nitrogen gas may be preferred because it does not leave any traces within the sample while carbon dioxide may be preferred because it dissolves better in liquid. Nevertheless, the choice of gas selection is up to the user. Pressurized effervescent liquid exits from a pressure vessel PB to be used with filter arrangements. There are valves associated with each of the pressurized gas containers that may be used to relieve pressure in the lines when the system is inactive. 
     Prior to discussing the filter arrangements, in the lower left of  FIG. 29 , four rinse/waste bottles PC are illustrated. Each of these bottles is dual purpose in that originally three of the bottles are filled with rinse liquid as temporary supply containers while the fourth bottle is empty as a receiving container. The valve and piping may be arranged such that, for example, rinse liquid transported through the rinse line PD provided by bottle  2  and washed through the filter arrangement is then returned the waste line PE into the empty bottle  1 . The valving may now be changed such that rinse liquid may be taken from another bottle, such as bottle  3 , and discharged into what was empty bottle  2 . In this situation, bottle  1  is re-designated as a receiving container. The clean rinse liquid from bottle  2  has been depleted while the rinse liquid has now filled bottle  1 . This toggling arrangement may continue until the clean rinse water from each of the bottles  2 ,  3 , and  4  has been depleted and all but one of the bottles is filled with waste solution. Rinse liquid from the bottles is moved through the rinse line and the waste lines using vacuum generated by the vacuum pump PF. A drain separator PG is used to separate liquid from the vacuum line to the vacuum pump PF. 
     Each filter arrangement has associated with it vent lines PI to enhance flow over the filters and also to clear the lines from fluid at the end of the process. 
     While the configuration of valves for the aspiration, rinsing, and extraction step is more complex than in earlier described embodiments, the primary goal of minimizing space with fewer valves is achieved. Additionally, by providing multiple bottles with the intention of utilizing one at a time for water supply and another for waste supply, space for the device may be further reduced. 
     The filter arrangements illustrated on the top half of the schematic of  FIG. 29  utilize the cartridges having disposable dual membrane filters utilizing slider valves to achieve the necessary configurations for filtering. 
     Attention will now be focused upon a portion of the process diagram focusing upon the configuration of a particular filter cartridge and the process flow associated with that filter cartridge when positioned in different filter configurations. 
     Just as with previous embodiments, the discussion will be directed to the six stages including 1) first aspiration of sample; 2) first rinse; 3) first extraction; 4) second aspiration of sample; 5) second rinse; and 6) final extraction. 
     For consistency, reference numbers for similar items will be numbered similarly as in previous embodiments but will be in the  400  series. 
       FIG. 19  illustrates the filter arrangement  400  having an inlet  430  for the fluid/particle mixture and suction outlets  440 A,  440 B. Additionally, two rinse liquid inlets  470 A,  470 B also function as foam inlets  480 A,  480 B. Outlet  435  is utilized to collect the separated particles. Separate filter elements  425 A,  425 B, shown in phantom in  FIG. 19 , are mounted behind covers  425 C and  425 D and are mounted upon the filter arrangement body  405 . 
     Directing attention to  FIGS. 20 and 21 , a slider valve  490  is movable within the filter arrangement body  405 . Slider valve  490  has configured upon its surface a plurality of different channels  492  which align with a plurality of channels  494  ( FIG. 19 ) within the filter arrangement body  405 . Slider valve  490  moves laterally within the slider valve channel  496  ( FIG. 20 ) and may be precisely indexed at different positions to configure the filter arrangement for different stages. 
       FIG. 22  illustrates the arrangement similar to  FIGS. 12A-12B  whereby vacuum is applied to the suction outlet  440 A and the fluid/particle mixture is drawn in through the inlet  430 . Tube  432  associated with the inlet  430  is flexible tubing which is compressed between two rollers (not shown) operated by gears  434 A,  434 B and are rotatable to extend the inlet  430  away from the body  405  into a container to extract the fluid/particle mixture. Rotation of the gears in a first direction A and A′ extends the tube  432  into the downward position as shown in phantom by  432 ′ in  FIG. 22  into a container  433 , also shown in phantom in  FIG. 22 , to receive a sample. Rotation of the gears in direction B and B′ will retract the flexible tube  432 . 
     In this configuration the fluid/particle mixture is aspirated through the filter element  425 A and the residual liquid is removed from the suction outlet  440 A such that particles are deposited upon the upper surface for the filter element  425 A. The flow path of the fluid is illustrated by arrows  467 . 
     Directing attention to the process flow diagram of  FIG. 22A , the inlet  430  of the filter cartridge  400  is submerged within a liquid sample in the container  433 . Vacuum pump PF creates a vacuum in line AA which extends into bottle B 1  to create a suction therein. The suction extends into waste line BB through the connection with bottle B 1 . As a result, sample liquid is drawn up through the inlet  430 , over the filter element  425 A and the waste liquid passes through the filter element  425 A and is then discharged through the suction outlet  440 A along lines CC into lines BB where the liquid waste is deposited in originally-empty bottle B 1  with retentate particles retained within the filter element  425 A of the filter cartridge  400 . 
     With the particles deposited upon the surface of filter element  425 A, slider valve  490  is indexed to a new location as illustrated in  FIG. 23  to engage different channels and port in the slider valve  490  and channels  492  in the body  405 . Rinsing fluid is now introduced into the rinse inlet  470 A and travels along the path illustrated by arrows  467  from inlet  470 A through the filter element  425 A and exiting through the suction outlet  440 A. 
       FIG. 23A  shows the process flow diagram for the rinse step just described with respect to  FIG. 23 . In particular, the vacuum pump PF still maintains a suction in line AA which creates a suction in bottle B 1  back through line BB to line CC through line DD and into line EE where rinse liquid is extracted from bottle B 2  and transported through lines EE and DD to rinse inlet  470 A of the filter cartridge  400  where the retained particles are rinsed. The rinse liquid then exits the filter cartridge  400  at the suction of  440 A where it proceeds through lines CC and BB and is discharged into bottle B 1 . Note that in both  FIGS. 22A and 23A , rinse liquid is extracted from bottle B 2  and discharged into bottle B 1 . 
     Utilizing the slider valves in certain indexed positions, the slider valve  490  and the body  405  are aligned such that certain channels that are not utilized in a particular configuration are still connected and thereby receive fluid. As an example, in  FIG. 23  channel  499 A is exposed to fluid. However, the channel dead-ends and, as a result, fluid accumulates within the channels  499 A and  499 B. Instead of arrows indicating flow, each of these channels is marked with an “x”. To avoid contamination, however, these channels must be cleared and, for that reason, there is a secondary rinse step. 
       FIG. 24  illustrates this secondary rinse step which exists for the sole purpose of flushing channels  499 A,  499 B for subsequent processes. In this instance, the slider valve  490  is indexed further down such that inlet  470 A conveys fluid and flushes the channels  499 A,  499 B where the residual fluid is removed through the suction outlet  440 A. There is no comparable step described in the previous embodiments. 
     From an inspection of  FIGS. 23 and 24 , it should be noted that in each configuration, rinse liquid is provided through inlet  470 A and is extracted through the suction outlet  440 A. The sole purpose of the arrangement illustrated in  FIG. 24  is to purge fluid from the channel dead ends and the external configuration of the filter cartridge  400  is identical. For that reason, the process flow diagram illustrated in  FIG. 23A , discussed with respect to  FIG. 23 , applies equally to the filter configuration found in  FIG. 24  and a separate process flow diagram is not included herewith. 
     With the channels clear and the particles deposited upon the filter element  425 A, as illustrated in  FIG. 25 , the slider valve  490  is once again indexed to engage a series of different ports and channels such that foam is now introduced into the foam inlet  480 A and follows the path indicated by arrows  467  and over the top of the filter element  425 A; and particles are removed from the top of the filter element  425 A and deposited upon the top of the filter element  425 B with the residual foam exiting at the suction outlet  440 B. This arrangement is similar to that shown in  FIGS. 14A-14B  of the previous embodiment but, furthermore, encompasses the configuration illustrated in  FIGS. 15A-15B  whereby particles aspirated from the top surface of the filter  425 A are removed therefrom and deposited upon the top surface of filter element  425 B. The foam passes through the filter element  425 B where it breaks down into a liquid and is discharged through suction outlet  440 B. Unlike the previous embodiment, there is no intermediate reservoir in this configuration. It should be noted in this configuration that the rinse inlet  470 A and the foam inlet  480 A are the same. Briefly directing attention to  FIG. 22 , enlargement “A” shows details of this inlet. Note that feature C highlights that the profile of the inlet port is conical. The conical port gives a good seal without the use of elastomers. This conical seal is based upon the same principal as Luer ports seen in syringes. 
       FIG. 25A  illustrates the process flow diagram associated with the configuration just described with respect to  FIG. 25 . In particular, foam is provided from the pressure vessel PB 1  through lines EE where it is introduced at the foam inlet  480 A over the face of the filter element. Displaced particles from the filter element are then deposited upon the face of the filter element at which time the foam is reduced to a liquid to which exits at the vacuum outlet  440 B and travels through lines CC and BB to be deposited in bottle B 1 . While the pressure of the foam may be sufficient to move the liquid from suction outlet  440 B into bottle B 1  without the vacuum suction, to make the process more efficient, the vacuum pump maintains suction through line AA into bottle B 1  to enhance the flow of the liquid into bottle B 1 . 
     Thereafter, as illustrated in  FIG. 26 , rinse fluid is introduced at inlet  470 B and follows the path indicated by arrows  467  and to rinse the top surface of the filter element  425 B wherein the residual fluid is removed at the suction outlet  440 B. This arrangement is equivalent to the arrangement illustrated in  FIGS. 16A-16B . 
       FIG. 26A  shows the process flow for the rinse step just described with respect to  FIG. 26 . In particular, the vacuum pump PF still maintains a suction in line AA which creates a suction in bottle B 1  back through line BB to line CC through line DD and into line EE, where rinse liquid is extracted from bottle B 2  and transported through lines EE and DD to liquid inlet  470 B of the filter cartridge  400 , where the retained particles are rinsed and the rinse liquid exits the filter cartridge  400  at the suction of  440 B, where it proceeds through lines CC and BB and is discharged into bottle B 1 . Note again that in both  FIGS. 22A and 23A , rinse liquid is extracted from bottle B 2  and discharged into bottle B 1 . 
     Briefly returning to  FIG. 26 , note channel  499 C does not have continuous flow and the fluid therein becomes stagnant. This channel is marked by “x” and a second rinse step is now required to purge this fluid. 
       FIG. 27  is a secondary rinse step not found in the previous embodiments whereby the slider valve is further indexed such that now water is still introduced at inlet  470 B. Slider valve  490  is indexed such that channel  499 C is flushed with rinsing fluid which travels in the direction of arrow  467  and exits at the vacuum outlet  440 B. 
     From an inspection of  FIGS. 26 and 27 , it should be noted that in each configuration, rinse liquid is provided through inlet  470 B and is extracted through the suction outlet  440 B. The sole purpose of the arrangement illustrated in  FIG. 24  is to purge fluid from the channel dead ends and the external configuration of the filter cartridge  400  is identical. For that reason, the process flow diagram illustrated in  FIG. 26A , discussed with respect to  FIG. 27 , applies equally to the filter configuration found in  FIG. 27  and a separate process flow diagram is not included herewith. 
     Particles are now deposited upon the top surface of filter element  425 B in a configuration similar to that illustrated in  FIGS. 17A-17B  of the previous embodiment. 
     As illustrated in  FIG. 28 , at this time, foam is introduced at the foam inlet  480 B and travels in the direction indicated by arrow  467  over the face of the filter element  425 B to displace particles from the face of the filter element such that the filtered particles exit from the outlet  435 . This arrangement is similar to that illustrated in  FIGS. 17A-17B  of the previous embodiment. 
       FIG. 28A  shows the process flow for the arrangement just described with respect to  FIG. 28 . In particular, foam is provided by pressure vessel PB 2  through lines FF to the inlet  480 B of the filter cartridge  400  where the particles are removed from the face of the filter element  425 B and discharged at the outlet  435  to provide a high concentration of particles suspended in a relatively low volume of liquid for subsequent analysis. 
     When utilized in a system, a multiplicity of filter arrangements  400  exist and the slider valve  490  for multiple filter arrangements  400  are activated such that a number of separate operations may be performed simultaneously. In particular, a filter arrangement, also known as a concentrator will be used on a processor including a cylindrical carousel. Additionally the filter arrangement  400 , as illustrated, has alignment holes, and pins are utilized in these alignment holes. 
     It should be noted that the filter elements  425 A,  425 B are comprised of porous hydrophilic surfaces to permit liquid to pass therethrough but to restrict particles of a certain size. However, a portion of the filter elements  425 A,  425 B must be hydrophobic to permit passage of accumulated gasses generated during the filtering process. In particular, the foam utilized during the process creates gas that must be released to avoid restricting fluid flow. Also, a porous mesh, or screen, or damper  500  is provided adjacent to outlet  435  in the discharge flow path  502  to slow the exiting velocity of the concentrated solution from the filter arrangement. 
     Directing attention to  FIG. 29 , it should be appreciated that bottles  2 ,  3 , and  4  have liquid therein while bottle  1  is empty. In the past, a single container would have been sized to receive the liquid from all of the bottles resulting in a significantly larger container. The inventors have realized that by utilizing a single empty bottle with a volume sufficient to accept the liquid from another single bottle, it is possible to toggle the valving system such that there is always a single empty bottle into which the waste fluid may be directed after usage. In this manner, rather than have a single container to accept the volume of three bottles, it is possible to have a single container to accept the volume of one bottle so long as that container may alternate among the bottles. 
     Additionally, the flow meter PH is actually a mass meter used to measure the amount of volume that travels through the cassette. In the past, a peristaltic pump was used to fill an intermediate container with a known amount of rinse fluid and then the vacuum was used to pull that liquid through the filter. However, the inventors determined that it was more efficient to use only the vacuum to move fluid. While flow meters are available, the flow rate through the filter element depended upon the amount of clogging of the filter element so that the range of flows is great. Flow meters capable of measuring the flow are expensive and, therefore, another way to determine flow rate was needed. The mass meter used herein accumulates fluid that travels through the cartridge and evaluates the quantity of fluid entirely by weight. Once a specific weight representing a certain volume of fluid has been reached, the rinsing cycle stops. By measuring the weight of the fluid, utilizing a relatively simple scale, sufficiently accurate results are obtained without the need to use more sophisticated flow meters which are significantly more expensive and complex and at times have difficulty measuring the flow of the foam fluid. Therefore, the inventors have discovered a simple and elegant solution to determine the volume of flow over the filters using a simple technique based upon the weight of the cumulative fluid traveling therethrough. 
     While the arrangement described in  FIG. 29  has been described with respect to cartridges using slider valves, such an arrangement is applicable to the different other cartridges and filters described herein as well as other similar cartridges and filters used for tangential filtering. 
       FIG. 30  shows details of one such mass meter PH. In particular, the mass meter PH includes a canister  504 , associated with a filter, which rests upon a load cell  506 , such as a piezoelectric transducer. The weight of fluid within the canister  504  may be determined using this load cell  506 . In such a fashion, an accurate estimation of the volume of fluid travelling through each filter is provided by the weight of the fluid within the canister  504  associated with that filter without the need to use direct volume measuring devices. As previously discussed, such direct volume measuring devices are not ideal for variable flow, such as that through a filter which may be partially clogged, and are relatively expensive. 
     Just as the dual filtering arrangement illustrated in  FIGS. 18A and 18B  are configured so that the filter element  315  and the filter element  320  provide twice the membrane surface within the same channel volume, so too is the configuration illustrated in  FIG. 31 . 
     Directing attention to  FIG. 31 , a top element  600  includes the filter element  425 A while a bottom element  700  includes a filter element  525 A. A fluid particle inlet  630  is in fluid communication with a chamber  635  common to both the filter element  425 A and the filter element  525 A. Suction passageways  540 A,  540 B are located on opposing sides of the filter elements  425 A,  525 A to provide a vacuum to filter the particles contained within the fluid particle solution introduced at the fluid particle inlet  630 . In such a fashion, the filter element  425 A and the filter element  525 A provide twice the membrane surface with the same channel volume. 
     While what has been discussed so far is a rinse stage that rinses the particles with a rinse solution before the particles are wiped from the surface of the filter, the Applicant has also realized that in lieu of or in conjunction with the rinse stage, with the same cartridge configuration, the particles retained in the filter may be introduced through the same rinse inlet and the particles may then be irrigated with a stain suitable for Gram staining, such as crystal violet. Thereafter, the stained particles may be further rinsed or wiped from the filter for further processing. By introducing the stain suitable for Gram staining to the particles through the filter cartridge, not only is an external step eliminated, but time is saved. 
     While what has been discussed so far is the processing of a sample to extract particles such as bacteria or other microorganisms, it is still necessary to identify these particles. 
     The next portion of this disclosure is directed to a method for detecting, quantifying, gram type identification and micro-organisms presumptive identification, e.g., bacteria in urine samples. More particularly, the invention relates to a combination of the unique sample processing method, technology and system, hereinafter described, followed by microscopy image analysis which is fully automated to efficiently detect, quantify, and perform gram type identification performed on micro-organisms or other cells, in urine samples or other body fluids. 
     In general, current-day practice for identifying micro-organisms, e.g., bacteria in urine samples involves a complex, lengthy, and expensive process for identifying and specifying micro-organisms in microbiology labs. In this current process, the samples are accepted into the lab. These specimens are then sorted and labeled and then they are inoculated onto blood agar medium using a sterilized loop. These three steps for preparing the samples for analysis are manually done wherein each urine sample is swabbed onto the blood agar medium in a covered culture disk or plate. If there are 50 to 100 samples, each sample has to be individually prepared, requiring much time and energy. 
     The specimens are then inserted into a dedicated incubator for a 24-hour period. A day later, the lab technicians screen the specimens for positive and negative cultures. In general, most of the cultures are negative and are manually reported. The organisms for the positive cultures are isolated and suspended in a biochemical fluid. This involves suspension, dilution, vortexing and turbidity measurements resulting in biochemical waste products. Again, this process for preparing the urine samples for analysis is done manually by lab technicians and again requiring much time and energy, particularly if there are 50 to 100 urine specimens that need to be analyzed. 
     The positive cultures are then subjected to a species identification and antibiotics susceptibility testing exposing the suspensions to multiple reagents. After another 6 to 24 hour incubation period, the findings are interpreted and reported by lab technicians. This entire process generally takes 11 steps and 50 hours to obtain specimen results and the process is labor intensive. 
     There is a need, therefore, particularly for rapid detection, quantification, gram type identification and presumptive species identification of the above lab procedure to provide a more efficient, but less time consuming process which requires less labor. 
     The subject invention as disclosed herein meets this need. The sample preparation system so far described concentrates and purifies the particles of a specimen based on dead end filtration and wet foam extraction. This process can be performed in about 10 minutes. However, now the particles must be identified. 
     This process is illustrated in  FIG. 32  beginning with a sample which is then processed in accordance with the previously described details of the invention. Thereafter, the particles of the concentrated sample are subjected to gram staining with subsequent scanning through a microscope and thereafter image analysis. As a part of the gram staining process, the particles may be smeared upon a medium that is suitable for use with a scanning microscope. While such steps for processing the concentrated sample may be performed manually, they may also be performed using a specimen processor such as the Copan WASP® Walkaway Specimen Processor which is an instrument for liquid sample processing for microbiology. The system provides gram slide preparation which thereafter is suitable for a scanning microscope and a subsequent image analysis. 
       FIGS. 33-37  show the effectiveness of concentrating particles using the sample processing method described herein. As an example,  FIG. 33A  shows an untreated clinical urine specimen on blood agar after a culturing period. No bacteria is easily visible. On the other hand,  FIG. 33B  shows a treated clinical urine specimen in which the bacteria particle have been concentrated using the system described herein. After a culturing period on the same blood agar, colonies of bacteria are easily visible. This same observation holds true for the specimens found in  FIGS. 33C and 33D . 
     It is important to note that  FIGS. 33A-33D  are used only as an example of the effectiveness of the process to concentrate and purify a sample. The subject invention does not require culturing to identify organisms and, as a result, the time required to concentrating organisms for further analysis is substantially reduced. 
       FIGS. 34-37  are additional examples of the effectiveness of sample concentration in accordance with the subject invention. 
     Overall, the sample processor of the subject invention enables lower micro organisms concentration levels detection (e.g. 1 E4 CFU/ml for urine tract infection) and streamlines the current practice for analyzing urine samples. In addition to being fully automated, the sample processor is compact and self-contained. The sample processor does not require a sophisticated operator and rapidly processes the urine samples or specimens for the analysis. The suggested method increases efficiency, improves workload, saves time and money, and is easy to operate. The analysis can be performed in about ten minutes. 
     As a result, the sample processor output is a concentrated and purified version of the input fluid. Small particles and soluble material are removed from the sample while the amount of desired particles per fixed volume is increased. The purification aspect of the sample processor allows better staining by removing materials that interfere with the staining reagents. The purification aspect also removes clutter from the stained slide by removing small particles. The concentration aspect of the sample processor allows better detection since the field of view of the microscope sees only a limited volume of liquid placed on the side, so in low concentration, there may not be any elements of interest in many fields of view. 
     As a result, what has been described is a method for analyzing microbiological samples including a sample preparation unit followed by gram staining and smearing procedures (manual/automated) and analyzed by microscopy image analysis for detection (screening), quantification, gram type classification, and presumptive microorganism identification. 
     While specific embodiments of the invention have been described in detail, it will be appreciated by those skilled in the art that various modifications and alternatives to those details could be developed in light of the overall teachings of the disclosure. The presently preferred embodiments described herein are meant to be illustrative only and not limiting as to the scope of the invention which is to be given the full breadth of the appended claims and any and all equivalents thereof. 
     While specific embodiments of the invention have been described in detail, it will be appreciated by those skilled in the art that various modifications and alternatives to those details could be developed in light of the overall teachings of the disclosure. The presently preferred embodiments described herein are meant to be illustrative only and not limiting as to the scope of the invention which is to be given the full breadth of the appended claims and any and all equivalents thereof.