Table 3.
Background mutation frequencies of pSJ2 and pSJ3.
| Plasmid | Total number of colonies | Number of mutant (white) coloniesa | Mutation rate (%) | Mutation frequencyb |
|---|---|---|---|---|
| pSJ2c | 39,119 | 1 | 0.0026 | 2.6 × 10−5 |
| pSJ2 (gapped, BND–cellulose purified)c | 28,406 | 3 | 0.011 | 1.1 × 10−4 |
| pSJ2 (gapped, gel purified)c | 26,313 | 14 | 0.053 | 5.3 × 10−4 |
| pSJ3 (gapped, BND–cellulose purified)c | 32,519 | 1 | 0.0031 | 3.1 × 10−5 |
| pSJ1d | – | – | 0.08 | 8.0 × 10−4 |
| M13mp2 (phage)e | – | – | 0.04–0.06 | 4.0–6.0 × 10−4 |
a
Plasmid DNA isolated from the four mutant colonies found with gapped pSJ2 and gapped pSJ3 (purified using BND–cellulose) was sequenced. Three of the mutations in the lacZα gene were C → T/G → A transitions. The fourth was a T → C/A → G transition.
b
Number of errors made per base.
c
Each data set with pSJ2 and pSJ3 was the sum of five independent experiments carried out in triplicate.
d
Data taken from a previous study [14].
e
Data taken from previous studies [12,22].