What are CD markers
Cluster of differentiation (CD) molecules are markers found on the surface of leukocytes and are used for their differentiation and investigation. These molecules often take the role of receptors or ligands and are essential for the cells they are found on. Usually, they initiate or participate in a signal cascade that changes cell behaviour, but in some cases CD proteins do not take part in cell signalling and instead they aid in cell adhesion.
During the 1st International Workshop and Conference on Human Leukocyte Differentiation Antigens (HLDA) in 1982, the CD nomenclature was established. Currently over 320 different clusters are defined in humans.
CD markers and Flow Cytometry
When researching leukocytes using flow cytometry, CD markers are often used. This technique is preferred because several surface markers on a single cell can be detected by the addition of a fluorophore to the CD antibody. Labelling the cells using this method relies on the fluorescently labelled CD antibody binding to the cell surface using the relevant CD antigen.