Recombinant Human CD28 Protein, Seafrom (CAT#: STEM-CT-0154-ZJF)

The Recombinant Human CD28 Protein manufactured by Seafrom is suitable for T-cell co-stimulation and immune responses.
CD28 (Cluster of Differentiation 28) is a glycoprotein belonging to the immunoglobulin (Ig) superfamily, characterized by a structure consisting of a single IgV-like extracellular domain, a transmembrane region, and an intracellular domain. In mice, CD28 is constitutively expressed as a disulfide-linked homodimer or monomer on the surface of all mouse T cells and developing thymocytes. CD28 interacts with the ligands B7-1 and B7-2, playing a crucial role in both T cell and B cell response pathways. Members of the B7/CD28 family can either enhance or antagonize T cell receptor signals, participating in the regulation of central and peripheral T cell tolerance. Consequently, CD28 is involved in T cell activation, induction of cell proliferation and cytokine production, as well as the promotion of T cell survival.
The lyophilized form of CD28 can be stored at 2-8°C for up to 24 months. For reconstitution, it can be dissolved in injectable water, saline, culture media, or PBS. After dissolution, aliquot into smaller portions, and store at -20°C for 6 months or -80°C for 12 months, avoiding repeated freeze-thaw cycles.

Expression Host: Human HEK293 cells
Synonyms: CD28, Tp44
Protein Sequence: The DNA sequence encodes human CD28 (GenBank: AAH93698.1) with an Fc tag at the C-terminus.
Molecular Weight: Recombinant human CD28 protein contains 366 amino acids, with a predicted theoretical molecular weight of 42.1 kD.
Purity: >95%, confirmed by SDS-PAGE gel and high-performance liquid chromatography (HPLC) analysis.
Endotoxin: <0.1 EU/μg (gel clot method)
Biological Activity: Immobilized human CD28 (Fc Tag) at a concentration of 1 μg/mL (100 μL/well) can bind to anti-mouse CD28 antibody in a linear range of 0.5-5 ng/mL.
Purification Method: Chromatographic purification
Composition: Sterile PBS (pH 7.4) freeze-dried powder containing 6% mannitol.

Optimal Stability
Gmp-Grade Quality
Low Batch-to-Batch Variability
Exceptional Specificity
Robust Bioactivity
Efficient and Reliable Performance

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