Figure 4.

Elongation of nascent DNA is retarded in Polɛ-depleted extracts. (A) Analysis of replication products by alkaline agarose gel electrophoresis. The replication reactions with Polɛ- or mock-depleted extracts were carried out for various times as indicated, and the purified products were analyzed by alkaline agarose gel electrophoresis followed by autoradiography. (B) The small DNA fragments produced in Polɛ-depleted extracts are double-stranded DNA. The replication reactions with the depleted extracts were carried out for various times as indicated. Purified products were divided in half and incubated with nuclease P1 (+) or control buffer (−). The digested products were then analyzed by neutral agarose gel electrophoresis followed by autoradiography.