A “Step Down” PCR-Based Technique for Walking Into and the Subsequent Direct-Sequence Analysis of Flanking Genomic DNA

The hunt for missing sequence data, whether it be in pursuit of full-length clones or for promoter sequences, can be laborious and expensive. Indeed, protracted efforts to find missing sequences by library screening can be fraught with the frustration of foraging through libraries that may lack the relevant clones. Such problems have led several researchers to describe alternative methods to clone and analyze DNA adjacent to known sequences.