| abstract |
A PROCESS AND APPARATUS FOR OBTAINING A DIFFERENTIAL WHITE BLOOD CELL COUNT IS DISCLOSED. A CYTOLOGICAL FIXING AGENT IS ADDED TO A SAMPLE OF BODY FLUID, SUCH AS BLOOD, CONTAINING WHITE BLOOD CELLS TO KILL THE BLOOD CELLS CONTAINED IN THE SOLUTION AND TO IMMOBILIZE THE CATALYTIC ENZYMES IN THE CELLS. THE ACTIVITY OF THE ENZYMES IS NOT SERIOUSLY IMPARRED, AND SOLUBLE COMPONENTS IN THE EXTRACELLULAR SOLUTION ARE NOT PRECIPITATED. WHEN THE BODY FLUID ALSO CONTAINS RED BLOOD CELLS A HEMOLYZING REAGENT IS ADDED AFTER THE FIXATION STEP TO CAUSE THE RED BLOOD CELLS TO RELEASE THEIR HEMOGLOBIN CONTENT INTO SOLUTION. ADDITION OF A SPECIFIC CYTOCHEMICAL SUBSTRATE, CHROMOGENIC PRECIPITATING COUPLING REAGENT, AND PH BUFFER CAUSES DEPOSITION OF AN INSOLUBLE DYE IN A SPECIFIC TYPE OF CELL CONTAINING THE IMMOBILIZED ENZYME. THE SOLUTION CONTAINING THE DYE BLOOD CELLS IS THEN PASSED THROUGH A PHOTOMETRIC COUNTER WHICH RAPIDLY AND ACCURATELY GIVES A COUNT OF THE DYED CELLS, USING DIFFRENT SPECIFIC SUBSTRATES FOR DIFFERENT ENZYMES CONTAINED IN SPECIFIC KINDS OF CELLS, ABSOLUTE AND RELATIVE COUNTS OF THE DIFFERENT CELLS CAN BE OBTAINED. |