Indirect ELISA analysis was performed by coating the plate with recombinant Human COMP protein, His tag (GTX140818-pro) (12.14-0.19 nM). Coated protein was probed with COMP antibody [HL3215] (GTX640855) (1 μg/mL). Goat anti-rabbit IgG antibody (HRP) (GTX213110-01) (1:10000) was used to detect the bound primary antibody.