Abstract: A method for analyzing blood enables one to isolate, detect, enumerate and confirm under magnification the presence of target cells which have expressed surface epitopes that indicate intracellular infection by various viruses or other infectious agents, and also cells which have expressed surface epitopes that indicate the presence of non-infectious medical conditions. The analysis involves the examination of cells in the blood sample for the presence or absence of particular surface epitopes while the blood sample is disposed in a centrifuged blood sampling container. The epitopic analysis for the presence or absence of infected cells, or cells which indicate the presence of non-infectious medical conditions relies on the detection of known target expressed epitopes. The target epitopes on the target cell types are epitopes which are also known to be absent on normal circulating cells in the blood.