TABLE 2.
Expression of β-Gal in cells using DNA-based KUN replicon vectors
| DNA construct (expression type) | Cell type | Cell passage | Amt of β-Gal (pg/cell)a |
|---|---|---|---|
| pKUNβrep2 (transient) | BHK21 | 186 ± 27 | |
| pKUNβrep3 (stable) | BHK21 | 2 | 194 ± 9 |
| BHK21 | 3 | 198 ± 14 | |
| BHK21 | 13 | 153 ± 4 | |
| BHK21 | 22 | 156 ± 7 | |
| Vero | 10 | 153 ± 6 | |
| HEp-2 | 15 | 154 ± 22 | |
| 293 | 20 | 122 ± 4 | |
| pKUNβrep4 (stable) | BHK21 | 6 | 130 ± 6 |
| A172 | 8 | 140 ± 12 |
a
Amounts of β-Gal were determined by using the β-Galactosidase Enzyme Assay System (Promega) by comparison with β-Gal concentration standards. To calculate β-Gal amounts per expressing cell, the amounts of β-Gal detected in the total volume of cell lysates were divided by the number of expression-positive cells at 48 h posttransfection in transient-expression experiments or by the total number of cells in stably expressing (100% β-Gal positive) cultures at indicated passages. The values are the means ± standard deviations for triplicate experiments.