A portion of amino acids 450-495 from the intracellular region of human CD5 was used as the immunogen for the recombinant CD5 antibody.
The CD5 antigen is a transmembrane glycoprotein expressed on the surface of practically all mature human T-cells (about 10% of CD4+ T-cells being CD5 negative). In immature (CD34+) T-cells, CD5 is weakly expressed, the intensity of expression increasing
