FIG. 2.

Effects of type I collagen on PCR when DNA templates were prepared with a GeneReleaser kit (A), by phenol-chloroform extraction (B), or by NaI treatment (C) in the presence of collagen. One-tenth of the final volume of DNA preparation was used for each PCR, so that the actual amount of collagen present in each PCR was 1/10 the amount indicated at the top of each lane if collagen was not removed by the extraction method. The use of a QIAamp tissue kit produced results similar to those obtained with a GeneReleaser kit. The positions of molecular size markers (M) are indicated on the left. The arrow indicates the position of the 599-bp DNA fragment.