TABLE 3.
Electroporationa of a linear DNA fragment (lacZ::kan) into cells containing λ Red-Gam-producing plasmid
| Expt | Strain | Plasmid (functions) | Titer of recombinantsb (104) | Titer of survivors (109) | Recombinants/survivor (10−5) |
|---|---|---|---|---|---|
| A | AB1157 (wild type) | pMC7 (none) | 0 | 5.0 | 0 |
| AB1157 (wild type) | pTP223 (gam, bet, exo) | 7.9 | 2.2 | 3.6 | |
| KM354 (recJ) | pTP223 (gam, bet, exo) | 22.6 | 3.2 | 7.1 | |
| KM353 (recD) | None | 0.0075 | 1.3 | 0.0058 | |
| JC9387 (recBC sbcBC) | None | 0.037 | 1.4 | 0.026 | |
| B | AB1157 (wild type) | pTP223 (gam, bet, exo) | 11.1 | 2.0 | 5.5 |
| JC10287 (recA) | pTP223 (gam, bet, exo) | 0.03 | 0.37 | 0.081 | |
| JC9239 (recF) | pTP223 (gam, bet, exo) | 4.5 | 3.3 | 1.4 | |
| KM354 (recJ) | pTP223 (gam, bet, exo) | 136.0 | 1.95 | 70.0 | |
| JC9387 (recBC sbcBC) | None | 0.85 | 2.3 | 0.37 |
a
Cells were electroporated with 0.2 μg (experiment A) and 0.9 μg (experiment B) of purified lacZ::kan linear DNA fragment, generated by digestion of pKM131 with BglI.
b
Titers of electroporation mixture (60 μl); recombinants were scored as kanamycin-resistant white colonies.