Description
The L203.rMab is a recombinant monoclonal antibody that was derived from L203 hybridoma cells. The L203.rMab specifically recognizes a monomorphic epitope on the extracellular region of human HLA-DR antigens which are human Major Histocompatibility Complex (MHC) Class II antigens. HLA-DR antigens are heterodimers comprised of two different type I transmembrane glycoproteins that are noncovalently-associated. The ~34 kDa HLA-DR alpha (HLA-DRα) chain is encoded by HLA-DRA whereas the ~28 kDa HLA-DR beta (HLA-DRβ) chains are encoded by one of the 4 different HLA-DRB loci (HLA-DRB1,3,4,5) that are located within the Human Leukocyte Antigen (HLA) Complex of chromosome 6. Each chain is comprised of an extracellular region with an IgSF domain, followed by a transmembrane sequence and a short cytoplasmic tail. The L203.rMab antibody recognizes a common determinant that is dependent on the association of HLA-DR alpha and beta chains. HLA-DR is variably expressed on B cells, activated T cells and NK cells, monocytes, macrophages, dendritic cells (DC), Langerhans cells, thymic epithelial cells, and tumor cell lines including B cell lines, myelomas, and some myeloid leukemias. HLA-DR functions in the presentation of peptide antigens to CD4+ T lymphocytes in the generation and regulation of adaptive immune responses. HLA-DR expressed on thymic stromal cells plays a key role in the positive and negative selection of CD4+ T cells during thymopoiesis. Certain HLA-DR alleles, polymorphisms or aberrant expression patterns are associated with susceptibility to diseases including autoimmunity and cancer. L203 antibody binding is reportedly blocked by the L243 monoclonal antibody suggesting that the two antibodies recognize crossreactive or spatially related determinants on HLA-DR.
BD® CompBeads can be used as surrogates to assess fluorescence spillover (compensation). When fluorochrome conjugated antibodies are bound to BD® CompBeads, they have spectral properties very similar to cells. However, for some fluorochromes there can be small differences in spectral emissions compared to cells, resulting in spillover values that differ when compared to biological controls. It is strongly recommended that when using a reagent for the first time, users compare the spillover on cells and BD® CompBeads to ensure that BD® CompBeads are appropriate for your specific cellular application.
Store undiluted at 4°C and protected from prolonged exposure to light. Do not freeze. The monoclonal antibody was purified from tissue culture supernatant or ascites by affinity chromatography. The antibody was conjugated to the dye under optimum conditions that minimize unconjugated dye and antibody.
1. Please refer to www.bdbiosciences.com/us/s/resources for technical protocols.
2. Please refer to http://regdocs.bd.com to access safety data sheets (SDS).
3. For U.S. patents that may apply, see bd.com/patents.
4. Caution: Sodium azide yields highly toxic hydrazoic acid under acidic conditions. Dilute azide compounds in running water before discarding to avoid accumulation of potentially explosive deposits in plumbing.
5. Since applications vary, each investigator should titrate the reagent to obtain optimal results.
6. The production process underwent stringent testing and validation to assure that it generates a high-quality conjugate with consistent performance and specific binding activity. However, verification testing has not been performed on all conjugate lots.
7. When using high concentrations of antibody, background binding of this dye to erythroid fragments produced by ammonium chloride-based lysis, such as with BD Pharm Lyse™ Lysing Buffer (Cat. No. 555899), has been observed when the antibody conjugate was present during the lysis procedure. This may cause nonspecific staining of target cells, such as leukocytes, which have bound the resulting erythroid fragments. This background can be mitigated by any of the following: titrating the antibody conjugate to a lower concentration, fixing samples with formaldehyde, or removing erythrocytes before staining (eg, gradient centrifugation or pre-lysis with wash). This background has not been observed when cells were lysed with BD FACS™ Lysing Solution (Cat. No. 349202) after staining.
8. For fluorochrome spectra and suitable instrument settings, please refer to our Multicolor Flow Cytometry web page at www.bdbiosciences.com/colors.
9. An isotype control should be used at the same concentration as the antibody of interest.
10. Cy is a trademark of Global Life Sciences Solutions Germany GmbH or an affiliate doing business as Cytiva.
11. Please observe the following precautions: We recommend that special precautions be taken (such as wrapping vials, tubes, or racks in aluminum foil) to protect exposure of conjugated reagents, including cells stained with those reagents, to any room illumination. Absorption of visible light can significantly affect the emission spectra and quantum yield of tandem fluorochrome conjugates.
12. Tandem fluorochromes contain both an energy donor and an energy acceptor. Although every effort is made to minimize the lot-to-lot variation in the efficiency of the fluorochrome energy transfer, differences in the residual emission from the donor may be observed. Additionally, multi-laser cytometers may directly excite both the donor and acceptor fluorochromes. Therefore, we recommend for every tandem conjugate, a matched individual single-stain control be acquired for generating a compensation or spectral unmixing matrix.
13. Human donor specific background has been observed in relation to the presence of anti-polyethylene glycol (PEG) antibodies, developed as a result of certain vaccines containing PEG, including some COVID-19 vaccines. We recommend use of BD Horizon Brilliant™ Stain Buffer in your experiments to help mitigate potential background. For more information visit https://www.bdbiosciences.com/en-us/support/product-notices.
