surfacemarker

Surfacemarker is a term used in biology to refer to molecules located on the plasma membrane of cells that are used to identify, classify, or characterize cell types, states, or lineages. Typically these markers are proteins or glycoproteins, such as receptors, adhesion molecules, or glycosylated epitopes, and they can be detected by antibodies.

These surfacemarkers are detected using techniques such as flow cytometry, immunohistochemistry, immunofluorescence, or mass cytometry. In clinical and research settings, surfacemarker-based approaches enable immunophenotyping and cell sorting, allowing the isolation of specific cell populations such as hematopoietic stem cells or various immune subsets.

Examples include CD4 and CD8 on T cells, CD19 on B cells, CD34 on hematopoietic progenitors, and CD56 on natural killer cells. In cancer, aberrant surfacemarker expression helps classify leukemias and lymphomas and monitor treatment response.

Marker expression can be influenced by activation, differentiation, or the microenvironment, so panels of markers are often preferred to a single surfacemarker. Interpretation requires context, including species and tissue type, and antibodies must be validated to minimize cross-reactivity.

Surfacemarker is a widely used term and is often considered synonymous with the broader concept of a cell surface marker. See also: CD markers, flow cytometry, immunophenotyping, cell sorting, hematopoietic stem cells.