Antibody (Ab) Homologous Competition (BMAX & Kd)

A homologous competition is a concentration response curve with an unlabeled compound that is identical to the radioligand being used. Radioligand concentration is constant in the experiment. Homologous competition experiments can be used as an alternative to saturation experiments to determine receptor affinity (Kd) and density (Bmax). When using [125I]-ligands, a non-radioactive iodo-ligand should be used if possible.

96-well antibody plate setup diagram for homologous competition radioligand binding assays. The antibody plate is designed to contain 1 compound (Columns 2 - 11, each in quadruplicate) in increasing concentrations and one reference antibody (Column 12), 25 μl per well at 5x of the final concentration of 10 μM. Column 1 contains buffer only, and is designated as total binding (0% inhibition). Column 12 contains reference antibody and is designated as nonspecific binding (100% inhibition). Rows A - D contain a low concentration of 125I-mAb and rows E - H contain a higher concentration of 125I-mAb.
96-well antibody plate setup diagram for homologous competition radioligand binding assays. The antibody plate is designed to contain 1 compound (Columns 2 - 11, each in quadruplicate) in increasing concentrations and one reference antibody (Column 12), 25 μl per well at 5x of the final concentration of 10 μM. Column 1 contains buffer only, and is designated as total binding (0% inhibition). Column 12 contains reference antibody and is designated as nonspecific binding (100% inhibition). Rows A - D contain a low concentration of 125I-mAb and rows E - H contain a higher concentration of 125I-mAb.
Antibody Homologos Competition Binding Data GraphPad
Antibody Homologos Competition Binding Data GraphPad
Antibody Homologos Competition Binding Data GraphPad