How to identify major immune cell types by their CD marker expression

Cluster of differentiation (CD) antigens are cell surface molecules that distinctly identify leukocytes and other cells relevant for the immune system (Engel et al. 2015). Immunologists commonly use CD markers to identify and isolate immune cell populations, subsets, and differentiation stages.

To date, there are more than 400 CD markers, which range from CD1 to CD371 (Engel et al. 2015). Other markers used to identify immune cells that are not classified under the CD nomenclature have also been defined, and include cytokines and transcription factors.

To find out which markers are expressed on certain immune cells, immunologists typically search the research literature for studies that have defined the expression of specific markers on particular cells. However, this approach can be quite time-consuming.

To help researchers save time and easily find markers for the most common immune cell types, Bio-Rad has developed an online CD marker database for mouse and human immune cells.

In addition to matching immune cells to their respective markers, the tool also provides a biological overview of each marker, including marker synonyms, functions and associated signaling pathways, as well as cellular localization.

For each of the major immune cell types, the tool also includes a detailed lineage diagram showing cell differentiation.

The main advantage of this online tool is that it allows scientists to speed up marker selection, thereby making experimental design easier.