About CD4
This gene encodes the CD4 membrane glycoprotein of T lymphocytes. The CD4 antigen acts as a coreceptor with the T-cell receptor on the T lymphocyte to recognize antigens displayed by an antigen presenting cell in the context of class II MHC molecules. The CD4 antigen is also a primary receptor for entry of the human immunodeficiency virus through interactions with the HIV Env gp120 subunit. This gene is expressed not only in T lymphocytes, but also in B cells, macrophages, granulocytes, as well as in various regions of the brain. The protein functions to initiate or augment the early phase of T-cell activation, and may function as an important mediator of indirect neuronal damage in infectious and immune-mediated diseases of the central nervous system. Multiple alternatively spliced transcript variants encoding different isoforms have been identified in this gene. [provided by RefSeq, May 2020]

About PE-Vio770
PE-Vio® 770 from Miltenyi Biotec is a red-emitting tandem fluorophore that combines pycoerythrin (PE) and Vio®770. The donor molecule, PE can be excited by the 488-nm blue, 532-nm green, or 561-nm yellow-green laser and and transfers energy to the acceptor molecule, Vio®770, which emitts light that can be captured with a 780/60 nm bandpass filter. PE-Vio®770 has an excitation peak at 565 nm and an emission peak at 775 nm and is a common alternative to PE-Cy7 and PE-H7.