| Treatments | Number of revertants (M ± SD)/plate and (MI) | ||||||||
| TA 98 | TA 100 | TA 102 | TA 97a | ||||||
| mg/plate | −S9 | +S9 | −S9 | +S9 | −S9 | +S9 | −S9 | +S9 | |
| Protocatechuic acid | 0.0a | 28 ± 2 | 24 ± 2 | 104 ± 15 | 95 ± 6 | 271 ± 18 | 461 ± 21 | 125 ± 15 | 96 ± 10 |
| 0.78 | 30 ± 7 (1.1) | 24 ± 6 (1.0) | 113 ± 17 (1.1) | 94 ± 11 (1.0) | 273 ± 6 (1.0) | 502 ± 34 (1.1) | 116 ± 10 (0.9) | 105 ± 16 (1.1) | |
| 1.56 | 26 ± 2 (0.9) | 22 ± 5 (0.9) | 104 ± 3 (1.0) | 100 ± 9 (1.0) | 261 ± 18 (1.0) | 475 ± 51 (1.0) | 121 ± 24 (1.0) | 101 ± 4 (1.1) | |
| 3.13 | 24 ± 2 (0.9) | 19 ± 4 (0.8) | 100 ± 9 (1.0) | 96 ± 6 (1.0) | 257 ± 6 (0.9) | 492 ± 37 (1.1) | 124 ± 12 (1.0) | 120 ± 2 (1.3) | |
| 4.69 | 25 ± 2 (0.9) | 21 ± 2 (0.9) | 94 ± 19 (0.9) | 97 ± 7 (1.0) | 299 ± 29 (1.1) | 498 ± 7 (1.1) | 124 ± 4 (1.0) | 113 ± 26 (1.2) | |
| 6.25 | 32 ± 9 (1.1) | 17 ± 3 (0.7) | 114 ± 10 (1.3) | 103 ± 7 (1.1) | 372 ± 10 (1.4) | 490 ± 21 (1.1) | 107 ± 6 (0.9) | 120 ± 18 (1.3) | |
| Ctrol+ | 2064 ± 87b | 1213 ± 33e | 1252 ± 124c | 1870 ± 69e | 1173 ± 47d | 1822 ± 102f | 1968 ± 77b | 1850 ± 67e | |