[Reparation of UV-damaged bacteriophage ed]

A repair of UV-damaged phage DNA in the "phage-host" system in accordance with the excision reparative mechanism is demonstrated by means of centrifugation in alkaline sucrose gradient of virulent 3H-thymidine labelled phage sd. The increase of the transfectants quantity of UV-irradiated DNA on uvr+ bacteria compatibly to uvr- bacteria evidences that the bacterial host participates in phage reparation. Caffeine inhibition of UV-irradiated phage sd survival confirms the participation of cell-host in reparation of UV-damaged phage.