Enzymatic synthesis of DNA probes complementary to a human variable number tandem repeat locus

Abstract

Both cloned and synthetic DNA probes complementary to human variable number tandem repeat (VNTR) loci have been used to detect restriction fragment length polymorphism. In this report, we describe an approach for the enzymatic synthesis of a DNA probe complementary to one VNTR locus. The probe is produced by annealing short synthetic oligonucleotides comprising single repeat units and enzymatically ligating them into a polymeric DNA probe. In HinfI digests of human genomic DNA separated by agarose gel electrophoresis, this ligated oligonucleotide probe (LOP) detects multiple polymorphic loci in the range of 3-23 kb producing highly informative DNA fingerprint patterns when different individuals are compared. The hybridization pattern is very stable even under high-stringency wash conditions. The LOP is more easily generated than cloned VNTR probes and is totally synthetic, avoiding problems associated with cloned probes including bacterial growth and maintenance as well as in vitro labeling.