Demonstration of a polymorphism in the gene ERCC1 by two DNA sequencing methods.

New methodology is important to the advancement of biomedical science. We recently described a polymorphism within exon IV of the ERCC1 gene, which is associated with an approximate 50% decrease in codon usage in some biological systems. In this report we show that this polymorphism can be readily demonstrated by standard manual DNA sequencing, and by a recently developed methodology which relies on spectrophotometric principles. The major advantage of this new methodology is that several-fold more samples can be assessed per unit time, at reduced cost.