Mouse antisize:Human CD4 Monoclonal Antibody, 0.1 mg

Mouse Anti-Human CD4 Antibody

Introduction

Mouse anti-human CD4 antibody is a monoclonal antibody generated in mice that specifically binds to human CD4 molecules. CD4 is a 55 kDa type I transmembrane glycoprotein expressed on the surface of T-helper lymphocytes, monocytes, macrophages, and dendritic cells. It is encoded by the CD4 gene located on human chromosome 12p13.

Target Protein: Human CD4

CD4 functions as a co-receptor with the T cell receptor (TCR) during antigen recognition by MHC class II molecules. It enhances TCR signaling and participates in the initiation of T-cell activation. CD4 has four extracellular immunoglobulin-like domains (D1–D4), a transmembrane region, and a cytoplasmic tail that interacts with the tyrosine kinase Lck, essential for downstream signal transduction.

Antibody Type

Mouse anti-human CD4 antibodies are typically IgG1 or IgG2a isotype monoclonal antibodies. These antibodies are derived using hybridoma technology by immunizing BALB/c or C57BL/6 mice with recombinant human CD4 protein or CD4+ human cells. Hybridomas producing high-affinity clones are selected for downstream production.

Clone Examples

Common clones include:

• Clone RPA-T4: Frequently used for flow cytometry, binds to domain D1.
• Clone OKT4: Used for immunohistochemistry and flow cytometry.
• Clone SK3: Strong binding affinity, suitable for multicolor cytometry panels.

Each clone differs in epitope specificity, affinity, and functional blocking ability.

Applications

Mouse anti-human CD4 antibodies are widely used in:

• Flow Cytometry (FACS): CD4+ cell enumeration in PBMCs or tissue digests.
• Immunohistochemistry (IHC): Detection of CD4+ T cells in formalin-fixed paraffin-embedded (FFPE) or frozen tissue sections.
• Immunofluorescence (IF): Co-localization of CD4+ T cells in microscopy studies.
• Western Blot (WB): Detecting denatured CD4 in lysates (though not all clones are suitable).
• Cell Sorting (MACS/FACS): Isolation of pure CD4+ T cell populations.
• Functional Blocking: Some clones can block CD4–MHC II interaction for mechanistic studies.

Conjugation Formats

Mouse anti-human CD4 antibodies are available in multiple formats:

• Unconjugated
• Fluorophore-conjugated (e.g., FITC, PE, APC, PerCP-Cy5.5)
• Biotinylated
• HRP-conjugated for ELISA and IHC
• Alexa Fluor® dyes for high-resolution fluorescence microscopy

Host Reactivity

• Species cross-reactivity: Minimal cross-reactivity with non-human primates. No known reactivity with mouse or rat CD4.
• Species specificity: Human-specific, must verify with blocking or isotype controls when working with mixed cell populations.

Storage & Stability

• Recommended storage at 4°C for short-term use.
• Long-term storage at -20°C or below, preferably in aliquots to avoid freeze-thaw cycles.
• Azide and carrier protein content should be checked for compatibility with downstream applications (e.g., functional assays or in vivo use).

Safety and Usage Notes

• Sodium azide in formulations may be toxic for in vivo applications—dialysis recommended.
• When used in blocking or neutralization, titer optimization is required.
• Antibody should be titrated for optimal signal-to-noise in each application.

Certificate of Analysis (COA) Components

Typical COAs include:

• Clone ID and isotype
• Binding specificity by ELISA or FACS
• Endotoxin level (EU/mg)
• Purity (>95%) via SDS-PAGE
• Sterility and mycoplasma testing

Quality Control

Each lot is tested by:

• Flow cytometry using human PBMCs
• ELISA binding assay against recombinant CD4
• IHC staining on human tonsil sections

References and Protocols

• NIH Flow Cytometry Panels: https://www.ncbi.nlm.nih.gov
• Antibody Database: https://antibodyregistry.org
• CD4 protein structure: UniProt P01730
• CD4–MHC II interaction models: Protein Data Bank (PDB ID: 1WIQ)