Table 1.

Spontaneous mutant frequencies for hTF/hMGMT × lacl and lacl mice

Mouse line	Transgenes	PFUs*	No. confirmed mutants	MF†
LC22l	MGMT + lacl	2,689,817	46	1.7  ± 0.25
LC22l	lacl	2,176,990	25	1.1  ± 0.23
LC26l	MGMT + lacl	2,753,112	55	2.0  ± 0.27
LC26l	lacl	1,830,100	38	2.1  ± 0.34

^*PFUs, plaque forming units. 

^†MF, mutant frequency (×10⁻⁵) ± standard error (×10⁻⁵).