Table 1: Evaluation of the mutagenicity of the S9 fraction that was obtained from rats that were treated with biotin in the Ames test.

DayChemicalDose ( g/plate)Number of His+ revertants/plate(a)
B−(b)B+(c)Positive control(d)

1B[a]P0
1
5
10
20
Induced revertants/ g(e)40.552.762.3*

7B[a]P0
1
5
10
20
Induced revertants/ g(e)16.515.037.4*

The mean number of revertant colonies identified in three replicates in two independent experiments.
(b)The liver S9 fraction from control rats.
(c)The liver S9 fraction from biotin-treated rats (2 mg/kg).
(d)The liver S9 fraction from phenobarbital-treated rats (60 mg/kg). -naphthoflavone (80 mg/kg) was used as a positive control.
(e)The slope at the origin was calculated using the SALANAL software program.
*Significantly different from B− and B+ ( ), as assessed using Student’s -test.