- GK1.5 (See other available formats)
- Regulatory Status
- Other Names
- L3T4, T4
- Rat IgG2b, κ
- Ave. Rating
- Submit a Review
- Product Citations
CD4 is a 55 kD protein also known as L3T4 or T4. It is a member of the Ig superfamily, primarily expressed on most thymocytes, a subset of T cells, and weakly on macrophages and dendritic cells. It acts as a coreceptor with the TCR during T cell activation and thymic differentiation by binding MHC class II and associating with the protein tyrosin kinase, lck.Product Details
- Antibody Type
- Host Species
- Mouse CTL clone V4
- 0.2 µm filtered in phosphate-buffered solution, pH 7.2, containing no preservative. Endotoxin level is <0.01 EU/µg of the protein (<0.001 ng/µg of the protein) as determined by the LAL test.
- The Ultra-LEAF™ (Low Endotoxin, Azide-Free) antibody was purified by affinity chromatography.
- The antibody is bottled at the concentration indicated on the vial, typically between 2 mg/mL and 3 mg/mL. Older lots may have also been bottled at 1 mg/mL. Please contact technical support for concentration and total µg amount, or use our Lookup tool if you have a lot number.
- Storage & Handling
- The antibody solution should be stored undiluted between 2°C and 8°C. This Ultra-LEAF™ solution contains no preservative; handle under aseptic conditions.
FC - Quality tested
Block, Costim, Depletion, IHC, IP - Reported in the literature, not verified in house
- Recommended Usage
Each lot of this antibody is quality control tested by immunofluorescent staining with flow cytometric analysis. For flow cytometric staining, the suggested use of this reagent is ≤1.0 µg per million cells in 100 µl volume or 100 µl of whole blood. It is recommended that the reagent be titrated for optimal performance for each application.
- Application Notes
Additional reported applications (for the relevant formats) include: blocking of CD4+ T cell activation1,4,11, thymocyte costimulation3, in vitro and in vivo depletion2,5-8, blocking of egg-sperm cell adhesion1,4, immunohistochemical staining of acetone-fixed frozen sections9,10, and immunoprecipitation1,2. The GK1.5 antibody is able to block CD4 mediated cell adhesion and T cell activation. Binding of GK1.5 antibody to CD4 T cells can be blocked by RM4-5 antibody, but not RM4-4 antibody. For in vivo studies or highly sensitive assays, we recommend Ultra-LEAF™ purified antibody (Cat. No. 100442) with a lower endotoxin limit than standard LEAF™ purified antibodies (Endotoxin < 0.01 EU/µg).
(PubMed link indicates BioLegend citation)
- Dialynas DP, et al. 1983. J. Immunol. 131:2445. (Block, IP)
- Dialynas DP, et al. 1983. Immunol. Rev. 74:29. (IP, Deplete)
- Wu L, et al. 1991. J. Exp. Med. 174:1617. (Costim)
- Godfrey DI, et al. 1994. J. Immunol. 152:4783. (Block)
- Gavett SH, et al. 1994. Am. J. Respir. Cell. Mol. Biol. 10:587. (Deplete)
- Schuyler M, et al. 1994. Am. J. Respir. Crit. Care Med. 149:1286. (Deplete)
- Ghobrial RR, et al. 1989. Clin. Immunol. Immunopathol. 52:486. (Deplete)
- Israelski DM, et al. 1989. J. Immunol. 142:954. (Deplete)
- Zheng B, et al. 1996. J. Exp. Med. 184:1083. (IHC)
- Frei K, et al. 1997. J. Exp. Med. 185:2177. (IHC)
- Felix NJ, et al. 2007. Nat. Immunol. 8:388. (Block)
AB_11150580 (BioLegend Cat. No. 100441)
AB_11149488 (BioLegend Cat. No. 100442)
AB_2810318 (BioLegend Cat. No. 100457)
AB_2810319 (BioLegend Cat. No. 100458)
AB_2810320 (BioLegend Cat. No. 100470)
AB_2810321 (BioLegend Cat. No. 100471)
- Ig superfamily, 55 kD
Majority of thymocytes, T cell subset
- TCR co-receptor, T cell activation
- MHC class II molecule
- Cell Type
- Dendritic cells, T cells, Thymocytes, Tregs
- Biology Area
- Molecular Family
- CD Molecules
- Antigen References
1. Barclay A, et al. 1997. The Leukocyte Antigen FactsBook Academic Press.
2. Bierer BE, et al. 1989. Annu. Rev. Immunol. 7:579.
3. Janeway CA. 1992. Annu. Rev. Immunol. 10:645.
- Gene ID
- 12504 View all products for this Gene ID
- View information about CD4 on UniProt.org
- I am unable to see expression of T cell markers such as CD3 and CD4 post activation.
- TCR-CD3 complexes on the T-lymphocyte surface are rapidly downregulated upon activation with peptide-MHC complex, superantigen or cross-linking with anti-TCR or anti-CD3 antibodies. PMA/Ionomycin treatment has been shown to downregulate surface CD4 expression. Receptor downregulation is a common biological phenomenon and so make sure that your stimulation treatment is not causing it in your sample type.
- Do you guarantee that your antibodies are totally pathogen free?
BioLegend does not test for pathogens in-house aside from the GoInVivo™ product line. However, upon request, this can be tested on a custom basis with an outside, independent laboratory.
- Does BioLegend test each Ultra-LEAF™ antibody by functional assay?
No, BioLegend does not test Ultra-LEAF™ antibodies by functional assays unless otherwise indicated. Due to the possible complexities and variations of uses of biofunctional antibodies in different assays and because of the large product portfolio, BioLegend does not currently perform functional assays as a routine QC for the antibodies. However, we do provide references in which the antibodies were used for functional assays and we do perform QC to verify the specificity and quality of the antibody based on our strict specification criteria.
- Does BioLegend test each Ultra-LEAF™ antibody for potential pathogens?
No, BioLegend does not test for pathogens in-house unless otherwise indicated. However, we can recommend an outside vendor to perform this testing as needed.
- Have you tested this Ultra-LEAF™ antibody for in vivo or in vitro applications?
We don't test our antibodies for in vivo or in vitro applications unless otherwise indicated. Depending on the product, the TDS may describe literature supporting usage of a particular product for bioassay. It may be best to further consult the literature to find clone specific information.
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