Method for analysis of subpopulations of blood cells

A method for identifying and enumerating cells of a subclass of blood cells in relation to cells of another subclass of blood cells comprising the steps of:

• (1) providing an aliquot from a blood sample,
• (2) selectively tagging cells of a first subclass of blood cells by incubating said aliquot with a first tagging agent which is selectively reactive with cells of said first subsclass, said first tagging agent having a measurable physical response to suitable stimulation;
• (3) selectively tagging cells of at least a second subclass of blood cells by incubating said aliquot with a second tagging agent which is selectively reactive with cells of said second subclass, said second tagging agent having a measurable physical response to suitable stimulation;
• (4) analyzing said aliquot, substantially a cell at a time, by subjecting said aliquot to suitable stimulation for both said first tagging agent and said second tagging agent while detecting said measurable physical response provided by said first tagging agent and said second tagging agent and capturing the data provided by said detection, said captured data being restricted to a predetermined range exceeding a threshold of a physical response value established by the intensity of the physical response conferred on the cells of interest by at least one of said tagging agents, and
• (5) differentiating cells of said first subclass of cells from said second subsclass based on occurrence of said measurable physical response of said first tagging agent and said second tagging agent.