A lambda phage has been isolated which specifically transduces the Escherichia coli pheS and pheT genes coding for the alpha and beta subunits of the phenylalanyl-tRNA synthetase (PRS). This phage transduces with high frequency (i) several temperature-sensitive PRS mutants to thermoresistance and (i
Plaque assay for lambda transducing phage carrying the E. coli metB gene
β Scribed by Johnson, James R. ;Liljestrand, Cheryl A.
- Publisher
- Springer
- Year
- 1983
- Tongue
- English
- Weight
- 402 KB
- Volume
- 190
- Category
- Article
- ISSN
- 0026-8925
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β¦ Synopsis
A halo plaque assay has been developed for the detection of nondefective lambda transducing phage carrying functional alleles of the metB gene of Escherichia coli K12. The assay is based upon the production of phage plaques on lawns of metB- bacterial cells which are supplemented with limiting amounts of methionine and upon the subsequent transduction of methionine-starved cells in the lawn surrounding the plaques. The resulting prototrophic transductants give rise to a halo of bacterial growth surrounding the plaque. A precise genotype can be ascribed to the characteristic morphologies of selected haloes. This technique has general application for all biosynthetic markers.
π SIMILAR VOLUMES
Lambda transducing phages carrying the excision repair genes uvrA+ and uvrC+ were selected from a pool of lambda phages carrying EcoR1 fragments of E. coli DNA. These phages and also lambdauvrB+ (obtained from Gottesman) were used to make lysogens of excision-defective strains carrying uvrA-, uvrB-