Reagent and process for the identification and counting of biological cells

A process for the identification and counting of biological cells in a sample, in particular in a blood sample, characterized in that it comprises the following operations:

• mixing and incubating the sample with a reagent for identifying and counting biological cells in a sample, comprising:
• a cell lysing agent comprising at least one detergent in a concentration allowing the lysis specifically of a given type of cell in the sample, and
• a stain capable of marking the intracellular nucleic acids of unlysed remaining cells, for identifying and counting the remaining cells in order to effect, in a single stage, the lysis of cells of a given type, in particular erythrocytes, the staining of the intracellular nucleic acids, and the fixing of the nucleate cells;
• measuring the resultant solution by flow cytometry using at least two measuring parameters selected from resistive volume, axial luminous diffraction, axial luminous transmission, orthogonal luminous transfusion, and fluorescence;
• and
• classifying and counting the nucleate cells in populations by means of the measured parameters.