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 Brilliant Ultraviolet 805
Brilliant™ UltraViolet 805 (BUV805) is a infrared-emitting tandem fluorophore that combines BD Horizon® BUV395 and an acceptor dye. It can be excited by the 355 nm ultraViolet laser and collected using a 820/60 bandpass filter. BUV805 has an excitation peak at 498 nm and an emission peak at 797 nm BUV805 has a low relative brightness, and is most commonly used for multicolor flow cytometry. This dye is part of the Brilliant™ UltraViolet dye family, developed and sold by BD Biosciences. This family of dyes uses BUV396 as the donor so that all dyes in the family can be excited by the 355 nm ultraViolet laser. Depending on the acceptor, the dyes in this family have different relative brightness ratings.