A method that uses the reaction of antibodies with antigens to determine the specific types of cell in a sample of blood cells, marrow cells, or lymph node cells. A tag is attached to antibodies that react with specific antigens in the cell. The tag can be identified by the laboratory equipment used for the test. As cells carrying their array of antigens are tagged with specific antibodies, they can be identified; for example, mylegenous leukemia cells can be distinguished from lymphocytic leukemia cells. This method helps to subclassify cell types which may, in turn, help to decide on the best treatment to apply in that type of leukemia or lymphoma.