Abstract
It has recently been shown that the complete inactivation of phage following treatment with HgCl2 can be reversed by precipitation of Hg++ with restoration of the phage to its original titre. 1 , 2 The phenomenon is interesting in that reactivation occurs after exposure to very concentrated HgCl2 solutions for long periods of time, conditions which produce irreversible loss of the growth function in even the most resistant spore forms of bacterial life. The suggestion was advanced 2 that this behavior spoke for the enzyme concept of phage rather than for the view that phage is composed of living protoplasm.
Further work seemed indicated to determine whether the reversible inactivation of phage with HgCl2 represented a special case or whether, as seemed likely, it was merely one example of a general property of phage. We wish to summarize here certain experiments on the cyanide-phage reaction.
1. Inactivation. Standard antistaphylococcal phage 3 suspended in beef infusion broth of pH 7.6 was mixed with an equal volume of 1/5,000 KCN (M/325) solution. The mixture was kept at room temperature for 24 hours after which time the following samples were taken: (a) 1 ml. immediately diluted 1/1,000 with broth for determination of residual [P]. (b) 10 ml. for reactivation.
2. Reactivation. To 10 ml. of inactivated phage was added 1 ml. of 2.74% AgNO3 and 2 ml. of 1% KCN, the purpose being to remove the CN ions from their union with phage and to combine them in the complex double ion Ag(CN)2 -. The latter ion does not form insoluble compounds with the cations present and therefore obviates the dangers of phage adsorption on a precipitate. Dilutions of 1 part of the reactivated mixture to 1000 parts of broth were made at once for subsequent titration.
Get full access to this article
View all access options for this article.