Table 1.
Frequency of drug-resistant colonies among cell cultures exposed to toxic drugs
| Drug | Cells | Time until resistant colonies, days | Colonies per 2 to 4 × 106 cells |
|---|---|---|---|
| Puromycin | CHE* | — | 0 (3 expts) |
| (1–20 μg per 10-cm | B 644† | 12, 18, 12 | 13, >80, >50‡ |
| dish) | D 313 | —, 11, 21 | 0, 3, 20 |
| M 853 | 14, 18 | 11, >100* | |
| SpoT 1 | 17, 10 | 2, >200* | |
| SpoT 2 | 10 | >200* | |
| Cytosine arabinoside | CHE | — | 0 (3 expts) |
| (0.25–10 μg per 10-cm | B 644 | 14, 15 | 40, >200 |
| dish) | D 313 | —, 15 | 0, 3 |
| M 853 | —, 15 | 0, >100 | |
| SpoT 1 | —, 10 | 0, >50 | |
| SpoT 2 | 30 | >200 | |
| Colcemid | CHE | — | 0, 0 |
| (0.1 μg per 10-cm dish) | B 644 | 26, 40 | 1, >200 |
| D 313 | —, 26 | 0, 3 | |
| M 853 | 26, 40 | 9, >100 | |
| (0.2 μg per 10-cm dish) | CHE | — | 0, 0 |
| B-01col† | 16, 9 | 10/7, 2 | |
| M-01col | 16, 9 | 28/75, 27 | |
| Methotrexate | CHE | — | 0 |
| (1.25–2.5 μg per 10-cm | B 644 | 11 | 82/17 |
| dish) | D 313 | 9 | 135 |
| M 853 | 16 | 91 | |
| SpoT 1 | 35 | 164 | |
| SpoT 2 | 35 | 68 |
*
CHE, diploid Chinese hamster embryo cells.
†
B 644, D 313, and M 854 are highly aneuploid, clonal lines of benzpyrene-, dimthylbenzanthracene-, and methylcholanthrene-transformed Chinese hamster cells; B-01col and M-01col are B 644 and M 854 cells resistant to 0.1 μg colcemid; and SpoT 1 and SpoT 2 are highly aneuploid spontaneously transformed Chinese hamster cells.
‡
Experiments in which, in addition to large colonies of cells, multiple small ones survived drug treatment, which was typically observed when selection was initiated at the lowest concentration listed in the table.