Anti-Hu CD45RA, HI100, PE, 100tests

This PE-conjugated monoclonal antibody from STEMCELL Technologies, clone HI100, targets an extracellular epitope on the CD45RA isoform of CD45, a type I transmembrane glycoprotein and member of the protein tyrosine phosphatase family. It is a mouse IgG2b, kappa antibody raised against CD45RA of human origin and shows reactivity with human and chimpanzee samples.

Alternative splicing of exons 4, 5, and 6 gives rise to several CD45 isoforms with molecular masses of 180–240 kDa; excision of exon 4 generates the ~220-kDa CD45RA isoform, which is expressed on naïve T cells, subsets of B cells and monocytes, and medullary thymocytes. CD45RA functions to enhance signaling through both the T cell receptor and B cell receptor. The HI100 antibody is commonly used in combination with antibodies against the CD45RO isoform to discern naïve and memory T cells and is useful for identifying the suppressor/inducer subset of CD4+ lymphocytes, as the proportion of CD45RA+ T cells typically decreases with age.

The reagent has been verified for flow cytometry and is also reported for that application. It has been verified for purity assessments of cells isolated with the EasySep™ Human Naïve CD4+ T Cell Isolation Kit II. For flow cytometry, the suggested use is ≤ 5 μL per 1 x 10^6 cells in 100 μL. The antibody was purified by affinity chromatography and conjugated with PE under optimal conditions, with the solution free of unconjugated PE. It is formulated in phosphate-buffered saline, pH 7.2, containing 0.09% sodium azide, 0.1% gelatin, and < 0.2% (w/v) bovine serum albumin. The product is stable at 2–8 °C when stored undiluted; do not freeze and protect from prolonged exposure to light.