The Binding Activity of Human DKK1 with Anti-DKK1 Recombinant Antibody. Activity: Measured by its binding ability in a functional ELISA. Immobilized Human DKK1 (CSB-MP006920HU(A4)) at 2 μg/mL can bind Anti-DKK1 recombinant antibody, the EC<sub>50</sub> is 1.283-2.544 ng/mL.