Cellocidin is a small neutral alkyne produced by a number of Streptomyces species, first discovered by Suzuki and colleagues in 1958. Cellocidin has a broad antibacterial, antifungal and antitumor profile due to its ability to react with endogenous thiols like cysteine and glutathione. Cellocidin occurs as a weak active in many bioassays using actinomycete crude extracts and is thus a useful standard for chemical and bioassay dereplication.