Analysis of hcDNA by two-dimensional gel electrophoresis. (A) When analyzed on an 8% polyacrylamide gel, hcDNA resolves into a series of discrete bands. In contrast, hcDNA only formed a few fuzzy bands on a 4% gel . (B) The first dimension shown in (A) was cut and loaded on a second gel (4% polyacrylamide), with or without DNA denaturation by heating the gel strip at 100°C. Without denaturation (left), hcDNA appears as a series of well-defined spots. After denaturation (right) all hcDNA spots show the two strands of the DNA fragment in equal amounts. The positions on the gels of hcDNA, of the linear double-stranded DNA fragment (linear double strand), and of both single strands (CA strand and TG strand) are indicated.