The 2B8 monoclonal antibody specifically binds to CD117 (c-Kit), a transmembrane tyrosine-kinase receptor that is encoded by the Kit gene (formerly dominant white spotting, W). The c-Kit ligand (also known as steel factor, stem cell factor, and mast cell growth factor) encoded by the Kit1 gene (formerly steel, SI), is a co-mitogen for hematopoietic stem cells, myeloerythroid progenitors and a mast-cell differentiation factor. The KitW and Kit1SI mutant alleles have similar pleiotropic effects on the development of melanocytes, germ cells, and the hematopoietic system. In the adult bone marrow, CD117 is expressed on hematopoietic progenitor cells, including CD90 (Thy-1) low, TER-119-, CD45R/B220-, CD11b (Mac-1)-, Ly-6G (Gr-1)-, CD4-, CD8-, and Sca-1 (Ly-6A/E)+ multipotent hemotopoietic stem cells, progenitors committed to myeliod and/or erythroid lineages, and precursors of B and T lymphocytes. This widespread expression of CD117 in hematopoietic precursors is consistent with the participation of c-Kit and its ligand in the regulation of several hematopoietic lineages. Intrathymic expression of c-Kit and c-Kit ligand suggest that CD117 is also involved in the regulation of some events during the development of T lymphocytes. CD117 is also expressed by mast cells and by dendritic cells found in the periarteriolar lymphocytoc sheaths (T-cell areas) of splenic white pulp. The mAb 2B8 reportedly does not block the action of c-Kit. This clone 2B8 had been reported to cross-react with rat.
Bead-based compensation or unmixing controls, such as BD® CompBeads or BD™ SpectraComp™, can be used as surrogates to assess fluorescence spillover when bound to fluorochrome-conjugated antibodies. Although these beads have spectral properties similar to cells, variations in spectral emission may occur, resulting in differing spillover values compared to biological controls. Therefore, it is considered best practice to compare the spillover obtained from cells and bead-based controls when using BD® CompBeads or BD™ SpectraComp™ for the first time, to ensure they are appropriate for the intended application.
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. Store undiluted at 4°C and protected from prolonged exposure to light. Do not freeze.
1. Please refer to www.bdbiosciences.com/us/s/resources for technical protocols.
2. 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.
3. Since applications vary, each investigator should titrate the reagent to obtain optimal results.
4. 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.
5. 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.
6. For fluorochrome spectra and suitable instrument settings, please refer to our Multicolor Flow Cytometry web page at www.bdbiosciences.com/colors.
7. An isotype control should be used at the same concentration as the antibody of interest.
8. Please refer to http://regdocs.bd.com to access safety data sheets (SDS).
9. 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.
10. 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.
11. Cy is a trademark of Global Life Sciences Solutions Germany GmbH or an affiliate doing business as Cytiva.
12. For U.S. patents that may apply, see bd.com/patents.
