4.6. Measurement of COX-2 and PGE2 Levels

The concentration of COX-2 and PGE₂ (R&D Systems, Inc., Minneapolis, MN, USA) was measured by ELISA according to manufacturer’s instructions. Briefly, in the measurement of COX-2, samples were added to COX-2 capture antibody-coated plate, and sequentially added detection antibody, streptavidin-HRP A, substrate solution to each well. The absorbance was then read at 450 nm. In the measurement of PGE₂, cell culture supernatants were added to the plate, and then primary antibody solution, PGE₂ conjugate, and substrate solution were added to each well in sequence. The absorbance was read at 450 nm.