Description
The WM53 monoclonal antibody specifically recognizes CD33 which is also known as Sialic acid-binding Ig-like lectin 3 (Siglec-3) or gp67. CD33 is a 67 kDa type I transmembrane glycoprotein that is variably expressed on myeloid progenitors, monocytes, macrophages, dendritic cells, neutrophils, basophils, mast cells, and on some activated T cells and NK cells. Normal lymphocytes, platelets, erythrocytes and pluripotent hematopoietic stem cells do not express the CD33 antigen. This glycoprotein reportedly functions as a sialic acid-dependent cell adhesion molecule and this function can be modulated by endogenous sialoglycoconjugates when CD33 is expressed on the membrane.
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. 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.
2. Researchers should determine the optimal concentration of this reagent for their individual applications.
3. 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.
4. Please refer to www.bdbiosciences.com/us/s/resources for technical protocols.
5. Please observe the following precautions: Absorption of visible light can significantly alter the energy transfer occurring in any tandem fluorochrome conjugate; therefore, we recommend that special precautions be taken (such as wrapping vials, tubes, or racks in aluminum foil) to prevent exposure of conjugated reagents, including cells stained with those reagents, to room illumination.
6. An isotype control should be used at the same concentration as the antibody of interest.
7. 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.
8. Please refer to http://regdocs.bd.com to access safety data sheets (SDS).
9. For fluorochrome spectra and suitable instrument settings, please refer to our Multicolor Flow Cytometry web page at www.bdbiosciences.com/colors.
10. Since applications vary, each investigator should titrate the reagent to obtain optimal results.
11. Cy is a trademark of Global Life Sciences Solutions Germany GmbH or an affiliate doing business as Cytiva.
12. 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.
Specifications

General

SourceMouse CD28, amino acids (Lys21-Lys149) (Accession# NM_007642), was expressed in 293E cells with a C-terminal human Fc IgG-6His tag.
Molecular MassThe 369 amino acid recombinant protein has a predicted molecular mass of approximately 42 kD. The DTT-reduced and non-reduced protein migrates at approximately 60 kD and 120 kD respectively by SDS-PAGE. The predicted N-terminal amino acid is Lys.
Purity>95%, as determined by Coomassie stained SDS-PAGE.
Formulation0.22 µm filtered protein solution is in PBS, pH 5.5.
Endotoxin LevelLess than 0.1 EU per µg of protein as determined by the LAL method.
Concentration10 and 25 µg sizes are bottled at 200 µg/mL. 100 µg size and larger sizes are lot-specific and bottled at the concentration indicated on the vial. To obtain lot-specific concentration and expiration, please enter the lot number in our Certificate of Analysis online tool.
Storage & HandlingUnopened vial can be stored between 2°C and 8°C for up to 2 weeks, at -20°C for up to six months, or at -70°C or colder until the expiration date. For maximum results, quick spin vial prior to opening. The protein can be aliquoted and stored at -20°C or colder. Stock solutions can also be prepared at 50 - 100 µg/mL in appropriate sterile buffer, carrier protein such as 0.2 - 1% BSA or HSA can be added when preparing the stock solution. Aliquots can be stored between 2°C and 8°C for up to one week and stored at -20°C or colder for up to 3 months. Avoid repeated freeze/thaw cycles.
ActivityImmobilized CD28 binds mouse B7.1 (1 µg/ml, BioLegend Cat. No. 555404) with an ED50 of 0.5 - 2.0 µg/mL.
ApplicationBioassay
Application NotesBioLegend carrier-free recombinant proteins provided in liquid format are shipped on blue-ice. Our comparison testing data indicates that when handled and stored as recommended, the liquid format has equal or better stability and shelf-life compared to commercially available lyophilized proteins after reconstitution. Our liquid proteins are verified in-house to maintain activity after shipping on blue ice and are backed by our 100% satisfaction guarantee. If you have any concerns, contact us at [email protected].
StructureDimer.
DistributionCD4, CD8 lymphocytes, immature CD3-, CD8+, CD4+ CD8+ cells, CD4- CD8- cells, and plasma cells.
FunctionActivation of naïve T cells, induction of cytokine production, cell survival, and expression of anti-apoptotic proteins including Bcl-XL.
InteractionAntigen presenting cells.
Ligand/ReceptorB7-1 (CD80) and B7-2 (CD86).
Biology AreaImmunology, Costimulatory Molecules
Molecular FamilyCD Molecules, Immune Checkpoint Receptors, Soluble Receptors
Antigen References1. Hansen JA, et al. 1980. Immunogenetics 5:429-39. 2. Gross JA, et al. 1992. J. Immunol. 149:380. 3. Coyle AJ, Gutierrez-Ramos JC. 2001. Nat. Immunol. 2:203. 4. Hebbar M, et al. 2004. Clin. Exp. Immunol. 136:388. 5. Boomer JS, Green JM. 2010. Cold Spring Harb. Perspect Biol. 8:a002436. 6. Rozanski CH, et al. 2011. J. Exp. Med. 208:1435. 7. Rozanski CH, et al. 2015. J. Immunol. 194:4717.
Gene ID12487
UniProtView information about CD28 on UniProt.org
Regulatory StatusRUO
Other NamesT-cell-specific surface glycoprotein CD28
BD 755606 RB780 Mouse Anti-Human CD33 WM53 (also known as WM-53) | IRIGHT