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 PerCP
Peridinin-Chlorophyll-Protein (PerCP) is a red-emitting fluorescent protein isolated from algae that can be excited by the 488 nm blue laser and captured with a 670/30 nm bandpass filter. PerCP exhibits a large Stokes' Shift, with an excitation peak at 482 nm and an emission peak at 675 nm. PerCP is was historically used in flow cytometry, however it is highly susceptible to photobleaching and has poor stability. Alternatives like BB700, NovaFluor Blue 690 or PerCP-eFluor™ 710 are preferred. PerCP is a generic dye that has no sole manufacturer.