Figure 3.
Time course of poly(dG)–poly(dC) synthesis reaction. Polymerase extension assay was performed as described in Materials and Methods with 0.2 μM (dG)10–(dC)10 and 20 μg/ml of Klenow exo−; the incubation was at 37°C. Aliquots were withdrawn each 15 min for 2 h 15 min. (A) The reaction products were resolved on 1% agarose gel and stained with ethidium bromide under conditions described in Materials and Methods. The marker bands of 1 kb DNA ladder (lane 1) are indicated to the left. Time-dependent products for 15, 30, 45, 60, 75, 90, 105, 120 and 135 min of the synthesis (lanes 2–10). (B) Dependence of the polymer length (in kb) estimated from (A) on the time of synthesis.