Plating efficiencies of modified lambda bio particles on temperature-sensitive hsd mutants of Escherichia coli K12.

Two mutants of Escherichia coli K12 that are temperature sensitive in cell growth and lambda phage production are shown to contain at least two mutations. One of the mutations in each of the isolates is in the hsd locus, and modification and restriction of lambda exhibits temperature sensitivity. One of the hsd mutations causes plaque formation by modified lambda bio particles that do not contain an intact ral gene to be temperature dependent.