The clone 4D3, also called 158-4D3, a mouse monoclonal antibody, recognizes a protein of 205 kDa-220 kDa cell surface isoform protein known as CD45RA of the leucocyte common antigen (LCA) of the CD45 antigen family. The CD45RA antigen is expressed mostly on naive CD4+, CD8+, γδ+ T, and on most B and NK lymphocytes. Generally, the CD45RA antigen density decreases upon activation.
We recommend that every lab carries out an initial titration study before running your samples to ensure that the optimal concentration is selected for your application.