The C3 set is 768 (8 x 96) unique crystallisation conditions grouped together based on chemical similarity. If you’ve got plenty of protein, and have a variation to try (seeding, co-factor, digested, different concentration) then you can set up 1536 unique crystallisation experiments using this set.
You need to be sure about the concentration of your protein, as a thousand perfectly clear or heavy precipitate drops makes for a depressing inspection schedule. Each screen is available discreetly, and we’ve found them useful if there is a broad class of chemicals that your protein appears to like. For a comprehensive list of the crystallants in each screen, use the C6 webtool.