Lipsky R H, Rosenthal R, Zahler S A
J Bacteriol. 1981 Dec;148(3):1012-5. doi: 10.1128/jb.148.3.1012-1015.1981.
We isolated defective specialized transducing phages of SP beta that carry one of the extracistronic suppressors, sup-3 or sup-44. Lysates containing these phages can be used in a simple spot test to determine whether an auxotrophic mutation can be suppressed. The sup-3 and sup-44 mutations are distinct, in that their suppression patterns differ for the markers hisA1, metC3, and thr-5; and they are not alleles.