>95% by SDS-PAGE
12 months from date of receipt, -20 to -70 °C as supplied. 6 months, -20 to -70 °C under sterile conditions after reconstitution. 1 week, 2 to 8 °C under sterile conditions after reconstitution. Please avoid repeated freeze-thaw cycles.
Complement receptor type 2 (CR2), also known as complement C3d receptor, Epstein-Barr virus receptor, and CD21 (cluster of differentiation 21), is a protein that in humans is encoded by the CR2 gene. CR2 is involved in the complement system. It binds to iC3b (inactive derivative of C3b), C3dg, or C3d. B cells express CR2 receptors on their surfaces, allowing the complement system to play a role in B-cell activation and maturation. Complement receptor 2 interacts with CD19, and, on mature B cells, forms a complex with CD81 (TAPA-1). The CR2-CD19-CD81 complex is often called the B cell co-receptor complex, because CR2 binds to opsonized antigens through attached C3d (or iC3b or C3dg) when the B-cell receptor binds antigen. This results in the B cell having greatly enhanced response to the antigen.
2μg(R: reducing conditions)