Automated microscopic cell analysis

Abstract

Disclosed in one aspect is a method for performing a complete blood count (CBC) on a sample of whole blood by metering a predetermined amount of the whole blood and mixing it with a predetermined amount of diluent and stain and transferring a portion thereof to an imaging chamber of fixed dimensions and utilizing an automated microscope with digital camera and cell counting and recognition software to count every white blood cell and red blood corpuscle and platelet in the sample diluent/stain mixture to determine the number of red cells, white cells, and platelets per unit volume, and analyzing the white cells with cell recognition software to classify them.

What is claimed is: 
     
         1 . A single-use test cartridge for use with an analyzer that includes an automated microscope for analyzing cells in a biological sample, comprising:
 a body that defines:
 a) a sample collection port and input channel for receiving the sample, 
 b) a valve having a pass-through conduit for metering a predetermined volume of sample, and fluidically coupled to the sample collection port and input channel when the valve is in a first flow position, 
 c) a vacuum channel for conveying a negative pressure relative to the pressure at the sample collection port fluidically coupled to the pass-through conduit when the valve is in its first flow position, 
 d) a diluent channel for conveying diluent and fluidically coupled to the pass-through conduit when the valve is in a second flow position, 
 e) a mixing chamber that is also fluidically coupled to the pass-through conduit when the valve is in the second flow position, and 
 (f) an imaging chamber fluidically coupled to the pass-through conduit when the valve is in a third flow position and where the pass-through conduit is also fluidically coupled to the mixing chamber by a connecting channel, 
   wherein the body is constructed and adapted to allow 1) the sample to flow from the sample collection port and input channel, through the pass-through conduit, and into the vacuum channel when the valve is in its first flow position; 2) diluent from the diluent channel and sample to flow through the pass-through conduit and into the mixing chamber when the valve is in its second flow position; and 3) the mixture of sample and diluent to flow through the pass-though conduit and into the imaging chamber when the valve is in its third flow position.   
     
     
         2 . The apparatus of  claim 1  wherein the body of the test cartridge further defines a photometric chamber with a vent hydraulically connected to the sample collection port and channel for measuring concentration of an analyte in the sample. 
     
     
         3 . The apparatus of  claim 1  wherein the body of the test cartridge further defines at least one diluent port hydraulically connected to the diluent channel for connection to a reagent supply. 
     
     
         4 . The apparatus of  claim 1  wherein the body of the test cartridge further defines at least one vacuum port for connection to a vacuum supply. 
     
     
         5 . The apparatus of  claim 1  wherein at least some of the hydraulic connections in the test cartridge and channels are visible through transparent portions of the body of the test cartridge to allow process monitoring. 
     
     
         6 . The apparatus of  claim 1  wherein the mixing chamber is hydraulically connected to the imaging chamber and a vacuum channel is connected to the mixing chamber wherein some of the mixture in the mixing chamber can be transferred to the imaging chamber directly instead of through the pass-through conduit. 
     
     
         7 . The apparatus of  claim 7  wherein the test cartridge includes a magnetic mixing bead in the mixing chamber. 
     
     
         8 . The apparatus of  claim 7  wherein the mixing chamber includes a passive mixer. 
     
     
         9 . The apparatus of  claim 1  wherein the body of the test cartridge further defines a plurality of vents to allow at least portions of the sample to be moved pneumatically in the test cartridge and at least one valve operative to direct at least portions of the sample to different locations in the test cartridge. 
     
     
         10 . The apparatus of  claim 1  further including a pump hydraulically connected to the sample collection port. 
     
     
         11 . The apparatus of  claim 16  wherein the pump includes a flexible bulb. 
     
     
         12 . The apparatus of  claim 1  wherein the body of the test cartridge further defines the sample collection port to be dimensioned to draw the sample in by capillary action. 
     
     
         13 . The apparatus of  claim 1  wherein the test cartridge is shaped like a microscope slide. 
     
     
         14 . The apparatus of  claim 1  wherein the test cartridge is preloaded with diluent. 
     
     
         15 . The apparatus of  claim 1  wherein the test cartridge is preloaded with stain. 
     
     
         16 . The apparatus of  claim 1  wherein the test cartridge is preloaded with a fluorescent stain. 
     
     
         17 . The apparatus of  claim 1  wherein the test cartridge is preloaded with a plurality of different stains. 
     
     
         18 . The apparatus of  claim 1  wherein the test cartridge is preloaded with a mixture of diluent and stain. 
     
     
         19 . The apparatus of  claim 1  further including a machine-readable imaging chamber depth indicator. 
     
     
         20 . The apparatus of  claim 1  wherein the body of the test cartridge defines the imaging chamber as having a depth of between about 20 to about 200 microns. 
     
     
         21 . The apparatus of  claim 1  wherein the body of the test cartridge defines sizes of the imaging chamber and metering chamber to provide a dilution ratio of about 10 to about 250. 
     
     
         22 . The apparatus of  claim 1  further including a diluent supply chamber hydraulically connected to the metering chamber. 
     
     
         23 . The apparatus of  claim 22  further including a pumping mechanism operative to drive diluent from the diluent supply chamber to the metering chamber. 
     
     
         24 . An analyzer for analyzing cells in a biological sample that includes a single-use test cartridge according to  claim 1  and further including a cradle for receiving the test cartridge, a mixer for mixing the sample and the diluent conveyed through the diluent channel in the test cartridge in the mixing volume, a digital microscope positioned to acquire digital images of the cells in the imaging chamber when the cartridge is in the cradle, and cell analysis logic responsive to the microscope to automatically perform cell analysis tasks on the acquired images, with the cell analysis logic including cell characterization logic and cell counting logic. 
     
     
         25 . A method of analyzing cells in a biological sample like blood comprising:
 a) measuring a predetermined amount of the blood sample,   b) mixing the sample with a diluent in a precise ratio,   c) transferring the diluted sample to an imaging chamber of fixed dimensions   d) taking images of the cells with an automated microscope   e) analyzing the images with cell recognition software, and   f) counting the number of cells per unit of volume.   
     
     
         26 . A method of analyzing cells in a biological sample like blood held in a test cartridge, comprising:
 a) measuring a predetermined amount of the blood sample in a portion of the test cartridge,   b) mixing the sample with a diluent in a precise ratio in the test cartridge,   c) transferring the sample to an imaging chamber of fixed dimensions in the test cartridge,   d) acquiring images of the cells in the imaging chamber after dilution with an automated microscope,   e) analyzing the acquired images with cell recognition software, and   f) counting the number of cells per unit of volume in the imaging chamber based on the acquired images.   
     
     
         27 . The method of  claim 26  wherein the step of mixing takes place in a mixing chamber in the cartridge before the step of transferring the sample to an imaging chamber. 
     
     
         28 . The method of  claim 26  wherein the step of mixing takes place at least in part in the imaging chamber. 
     
     
         29 . A reagent supply module for use with an apparatus that includes an automated microscope for analyzing cells in a biological sample held in a test slide, comprising:
 a) vessel for holding a diluent,   b) a metering mechanism hydraulically connected to the vessel,   c) a diluent output port hydraulically connected to the metering mechanism and constructed to hydraulically interface with a diluent channel on the test slide.   d) a vacuum chamber, and   e) a vacuum port constructed to hydraulically interface with a vacuum port on the test slide.   
     
     
         30 . A method of analyzing cells in a biological sample held in a test slide using an automated microscope, comprising:
 providing a reagent supply module that includes:   a) a vessel for holding a diluent,   b) a metering mechanism hydraulically connected to the vessel,   c) a diluent output port hydraulically connected to the metering mechanism and constructed to hydraulically interface with a diluent channel on the test slide.   d) a vacuum chamber, and   e) a vacuum port constructed to hydraulically interface with a vacuum port on the test slide, and   introducing diluent into the vessel.