For researchers wishing to screen for the appropriate coelenterazine derivatives to use, we offer this kit with 25 ug each of nine coelenterazine analogs: coelenterazine, coelenterazine <i>cp</i>, coelenterazine <i>f</i>, coelenterazine <i>fcp</i>, coelenterazine <i>h</i>, coelenterazine <i>hcp</i>, coelenterazine <i>i</i>, coelenterazine <i>ip</i>, and coelenterazine <i>n</i>.