Purity of staphylococcal delta-haemolysin obtained by three different procedures.

Summary Three methods at present available for the purification of staphylococcal δ-haemolysin were compared as to the purity and identity of the product obtained. None yielded a pure preparation of δ-haemolysin; one of the three preparations did not contain demonstrable δ-haemolysin when tested electro-phoretically, but it contained deoxyribonuclease, penicillinase, phosphatase and α-haemolysin. The second preparation had δ-haemolysin activity and was free of α-haemolysin, but it contained lipase, egg-yolk factor, esterase, deoxyribonuclease, penicillinase, phosphatase and hyaluronidase. The third preparation contained all of the products mentioned above, except phosphatase, and it also contained α-haemolysin, staphylokinase, lysozyme and caseinase. These findings are discussed with special reference to the requirement for criteria of purity in work with staphylococcal products.