Controlled Cleayage of Phage R17 RNA within the Virion by Treatment with Ascorbate and Copper (II)

A method is described for the degradation of R17 phage RNA in situ using vitamin C and copper (II). The procedure permits the controlled cleavage of the phage genome without affecting in any gross way the properties of the capsid proteins nor the secondary structure of the RNA. Losses of infectivity of the order of 6–7 logs were readily obtained without causing any detectable changes in the attachment capacity of phage nor in the structural integrity of the virion. Studies on the effect of oxygen, catalase, and superoxide dismutase on this reaction suggested that hydroxyl radicals generated from H 2 O 2 may be the reactive species responsible for the cleavage of phage RNA.