| Abstract: | Abstract— Biologically active f2-RNA, Obtained from bacteriophage f2, was inactivated by ultraviolet (u.v) light (2537 Å) with a quantum yield of 3.3 ± 0.3 times 10-3 when assayed in the dark with protoplasts of an F- strain of E. coli k12. Assay under “black light” gave a quantum yield of 2.7 ± 0.5 times 10-3 which was just enough lower to suggest that 17 per cent photorecovery of the u.v. lesions has taken place. Intact phage f2 was inactivated by u.v. radiation with a quantum yield of 0.7 ± 0.12 times 10-3, Thus the whole phage is much less sensitive than the free RNA. No evidence of photorecovery was found in u.v.-irradiated RNA phage 7S assayed in its host Pseudomonas aeruginosa. |
