Flow cytometry

Flow cytometry (FC) is a laser-based fluorescence detection method used to characterize cell antigens on large numbers of hematopoetic or lymphoid cells in suspension typically derived from peripheral blood, bone marrow aspirate or lymph node tissue. Flow cytometry instruments use a thin laminar flow of fluid to direct thousands of cells from a small diameter nozzle through a thin beam of laser light of a certain wavelength. The cells are categorized by size forward light scatter, cellular complexity or granularity side scatter and by antigen density fluorescence intensity for each 'CD' clusters of differentiation marker. The antigen distribution for thousands of cells is printed in graphical histograms which a pathologist interprets individually and collectively to determine the phenotype of dominant cell populations in leukemias and lymphomas of various types.