Stemcell, 100-1602, Anti-Mouse CD4 Antibody, Clone GK1.5

This monoclonal antibody reacts with mouse cluster of differentiation 4 (CD4), a 55 kDa single chain type 1 transmembrane glycoprotein belonging to the immunoglobulin (Ig) superfamily. CD4 contains four extracellular Ig-like domains; D1 - D4. CD4 is expressed at relatively high levels by most thymocytes and a subpopulation of T cells; T helper/inducer cells, and at lower levels on dendritic cells. Use this recombinant monoclonal antibody in applications requiring detection of CD4, such as flow cytometry (FC), immunohistochemistry (IHC), and immunofluorescence (IF).

Unlike humans, CD4 is not expressed by murine monocytes or macrophages. CD4 increases the affinity in the interaction between T cell receptor (TCR) and major histocompatibility complex II (MHC II) antigen complex by binding to a non-polymorphic region of MHC II and acting as a co-receptor to TCR in MHC II-restricted antigen recognition. CD4 also amplifies signals from TCR to the cytoplasm through the interaction of its intracellular domain with the cytoplasmic tyrosine kinases such as lymphocyte-specific protein tyrosine kinase (Lck). This monoclonal antibody is widely used as a phenotypic marker for CD4 expression. The RM4-5 clone can block binding of the GK1.5 antibody clone to CD4 on the cell surface. The GK1.5 antibody clone is also reported to be cross-reactive with Syrian hamster CD4.