TABLE 3.

rpoB and lacZ rates of mutations at different temperatures^a

Strain	Mutation rate (μ) per replication (10−8) at temp (°C)
	Rifr				Lac+
	30	34.5	37	43	34.5	37	43
WTb (CC107)		1.3	1.5	2.6	3.8	8.9	6.7
mutS::Tn10			120	93		3,600
mutS60		1.3	4.3	144	1.5	39	4,570
mutH126		3.9	8.7	46
mutL35	1.3	1.0	27	37
mutS60 mutL35	0.8	2.3	67	52

^aThe rpoB and lacZ mutation rates (μ) per replication were determined by first dividing the median number of Rif^r or Lac⁺ mutants by the average number of cells in a series of cultures to obtain the mutation frequencies and then calculating the mutation rate (μ) shown in this table from these values by the method of Drake (14).

^bWT, wild type.