Common CD markers used for the differentiation of leukocytes by flow cytometry.

Cluster of differentiation (CD) molecules are cell surface markers widely used in flow cytometry for the identification and characterization of leukocytes and their subsets. These markers, which behave in a variety of sorts, typically act as receptors, co-receptors, ligands or cell adhesion molecules that mediate various immune responses. Since cells often express multiple CD markers at any given time, utilizing a combination of CD markers is especially useful in determining a subpopulation.