Fig. 4. ( A ) Western blots for cyclooxygenase (COX)-1 ( left ) and COX-2 ( right ) using 100 ng purified COX-1 protein and 30 ng purified COX-2 protein. ( B ) Western blots for COX-1 ( left ) and COX-2 ( right ) proteins extracted from skin of the rat that was injected with carrageenan 6 h before with use of COX-1 and COX-2 antibodies and the preabsorbed antibodies with each specific antigen peptide. Ab = antibody.