Method for the determination of a differential white blood cell count

Abstract From the Canadian patent

This invention relates to a method and composition for the rapid determination of a differential white blood cell count in a sample, which method comprises: a) preparing a reagent solution comprising formaldehyde or paraformaldehyde;, a surfactant; a sugar or sugar alcohol; and, a buffer; and b) rapidly mixing said reagent solution with the sample to be analyzed to form a reaction mixture wherein, both said reagent solution and said sample are initially at room temperature; and, c) rapidly heating said reaction mixture to a temperature of from about 62°C to about 72°C in order to lyse the red blood cells in said sample and fix the white blood cells in said sample.