Gene diagnosis of phenylketonuria by capillary electrophoresis in a novel nongel sieving polymer solution

It is not possible to estimate DNA fragment lengths in undenatured buffer s ystems by the calibrating method because a conformation problem can occasio nally predominate. Although some authors use urea as a denaturant to elimin ate the influence of conformation on migration, they often experience the d ifficulty of loss of resolution. We have developed a novel sieving matrix w ith relatively low viscosity and good sieving ability, by which DNA standar d PBR322/HaeIII could be separated satisfactorily. The influence of DNA con formation can also be eliminated in the same system: which makes it possibl e to estimate the length of a DNA fragment more precisely. Gene diagnosis a nd family linkage analysis of Phenylketonuria (PKU) was performed as an app lication. A four-base-pair difference in length of the phenylalanine hydrox ylase (PAH) short-tandem repeat (STR) alleles could be separated and identi fied, which paved the way for diagnosis of PKU by capillary electrophoresis .