The mouse monoclonal antibody clone SK3 binds to human CD4. Human CD4 is a monomeric, approximately 59 kDa type I transmembrane glycoprotein and a member of the immunoglobulin superfamily. It comprises four extracellular immunoglobulin (Ig)-like domains (D1-D4), with the D1 domain specifically binding to the β2 domain of Major Histocompatibility Complex (MHC) class II molecules on antigen-presenting cells (APCs). This interaction is a co-receptor alongside the T Cell Receptor (TCR) during antigen recognition, facilitating TCR signaling and subsequent T cell activation. The cytoplasmic tail of CD4 is associated with the tyrosine kinase Lck, which is crucial for initiating the signaling cascade that leads to T-cell activation. CD4 is predominantly expressed on thymocytes and subsets of mature T cells, including T helper cells (Th17) and regulatory T cells (Treg), as well as on dendritic cells, monocytes, and macrophages. It plays a pivotal role in immune response modulation by aiding the activation of other immune cells, such as B cells and cytotoxic T lymphocytes, through cytokine release. Additionally, CD4 serves as a primary receptor for the Human Immunodeficiency Virus type 1 (HIV-1), which binds to CD4 and co-receptors CCR5 or CXCR4 to gain entry into T cells, leading to the depletion of these crucial immune cells and progression to Acquired Immunodeficiency Syndrome (AIDS). The SK3 antibody does not block the binding of alternative clone RPA-T4, suggesting that they recognize different epitopes.

PRODUCT DETAILS

Clone: SK3

Specificity: CD4

Reactivity: Human

Format: cFluor^® UV440*

Isotype: Mouse IgG1, k

Test Dilution: 5 µl/Test

Application: Flow Cytometry

Storage: 2-8°C protected from light. Do not freeze

Formulation: Phosphate-buffered saline, pH 7.2, containing 0.1% PEG 3350, 0.1% Pluronic F-68, 0.05% Tween-20, 0.09% sodium azide and 1% BSA (BSA Country of Origin USA)

Data Sheets: TDS | SDS

RECOMMENDED USAGE

Each lot of this antibody is quality control tested using flow cytometric analysis. For flow cytometric staining, the suggested use of this reagent is 5 μL per 1 million cells in a staining volume of 100 μL. If whole blood is analyzed, then use 5 μL per 100 μL. It is recommended that users titrate the antibody to obtain the optimal result for their specific application.

Please briefly centrifuge the reagent vial before use.

Use appropriate personal protective equipment per the product safety data sheet when using this product.

REFERENCES

Evans RL, et al. 1981. Immunol. 78:544

Arno A et al. 1999. J. Infect. Dis. 180:56

Muench M, et al. 1997. Blood 89:1364

For Research Use Only. Not intended for use in diagnostic procedures.

*Cytek^® cFluor^® UV440 is StarBright^™ UltraViolet 445 Dye, manufactured and provided by Bio-Rad, Inc.

StarBright is a trademark of Bio-Rad Laboratories, Inc. in certain jurisdictions. StarBright Dyes are manufactured and provided by Bio-Rad under an Agreement between Bio-Rad supplied to Cytek, being subject to certain conditions.