Flow Cytometry

Immunophenotypic Studies

Evaluating tumor cells for the presence of various cytoplasmic and nuclear antigens often provides useful diagnostic and prognostic information. The most common methods employed are flow cytometry and immunohistochemistry. The former is also used to perform lymphocyte subtyping studies on peripheral blood and bronchoalveolar lavage specimens.

Flow Cytometry

In this method, liquid suspensions of fresh cells (usually peripheral blood, bone marrow, or teased lymph node) are mixed with various monoclonal antibody tags. The tagged cells are then isolated and counted as they pass through a laser chamber. This method is particularly useful in studying hematopoietic malignancies (lymphomas and leukemias), where many of the pertinent antigens are lost by fixation. Flow cytometry is also used to perform lymphocyte subtyping (T and B cells, helper T4 and suppres- sor T8 cell ratios) and DNA analysis.

Specimen Requirements and Handling