Fig. 3. Multiple tissue semi-quantitative PCR. Multiplex PCRs with primer pairs for COX2 and a 315 bp fragment of the 18S ribosome were conducted with randomly primed killifish cDNA as a template. The 479 base pair COX2 fragment was amplified, in decreasing order, from gill, opercular epithelium, kidney, heart, stomach, intestine and brain. 18S was amplified approximately equally from the cDNA of all tissues. 100 bp ladder molecular mass markers were run in the lanes to the left and right of samples.