Anti-CD45RA (Leukocyte Common Antigen, LCA)

CD45 (leukocyte common antigen), the most common hematopoietic lineage marker, is a transmembrane glycoprotein tyrosine phosphatase with important roles in immune system signal transduction pathways. Antibody panels have been instrumental in identifying multiple isoforms, including CD45RA. Isoforms differ in their extracellular domain and are generated by alternative splicing of exons 4, 5 and 6 encoding peptide segments called A, B, and C, respectively. At least five different isoforms have been identified in humans: containing all three (ABC), two (AB and BC), one (B) or no (O) exons. A given antibody recognizes either every isoform (CD45 antibody) or only a subset ("restricted" CD45R antibody). The CD45RA antibody clone reacts with the ABC and BC isoforms (Schlossman et al, 1995). CD45RA has a molecular weight of 205-220kD. Isoform expression is regulated in lymphocyte type and activation-state dependent manners. CD45RA is expressed on subsets of T and B cells rendering the CD45RA antibody particularly useful for studying subpopulations. For example, naïve T lymphocytes express CD45RA containing the A exon which is lost after activation and replaced by CD45R0. In this regard, the CD45RA antibody is a useful naïve T cells marker since they express CD45RA, and activated or memory T cells are CD45RA negative and CD45RO positive (Schlossman et al, 1995). CD45RA is differentially expressed on lymphomas and the CD45RA antibody may also be used to help identify or classify lymphomas such as the CD45RA positive B from the CD45R0 positive T cell lymphomas. Researchers are encouraged to consult the scientific literature for additional information about CD45RA expression, including the use of antibody panels that include a CD45RA antibody for characterizing a given malignancy. Applications: Suitable for use in ELISA, Western Blot, Immunofluorescence, Flow Cytometry, Immunoprecipitation and Immunohistochemistry. Other applications not tested. Recommended Dilution: Flow Cytometry: 0.5-1ug/10e6 cells, Western Blot: 0.5-1ug/ml, Immunofluorescence: 1-2ug/ml, Immunoprecipitation: 1-2ug/500ug protein lysate, Immunohistochemistry (Frozen & Formalin fixed paraffin embedded): 0.5-1ug/ml/30min @ RT, Optimal dilutions to be determined by the researcher. Positive Control: Daudi, Raji, IM9, and human lymphocytes. Human lymph nodes and tonsils. Storage and Stability: May be stored at 4°C for short-term only. Aliquot to avoid repeated freezing and thawing. Store at -20°C. Aliquots are stable for 12 months. For maximum recovery of product, centrifuge the original vial after thawing and prior to removing the cap.