@article {Ji:January 1996:0888-7543:185, author = "Ji H.", author = "Francisco T.", author = "Smith L.M.", author = "Guilfoyle R.A.", title = "Rapid Restriction Mapping of Cosmids by Sequence-Specific Triple-Helix-Mediated Affinity Capture", journal = "Genomics", volume = "31", year = "January 1996", abstract = "

A simple and rapid strategy for restriction mapping based on sequence-specific triple-helix affinity capture (TAC) was developed. The strategy was applied to the analysis of cosmid clones by the construction of a new cosmid vector, ScosTriplex-II, containing two different triple-helix-forming sequences flanking the cloning site of the original SuperCos-1 cosmid vector. For restriction mapping, the recombinant cosmid DNA is digested with Not I restriction enzyme or with one of four intron-encoded endonucleases for excision of intact inserts followed by controlled partial digestion with a mapping enzyme used in conjunction with the corresponding methyltransferase. The partial digestion products are combined with biotinylated triple-helix-forming oligonucleotides to form a triple-helical complex. The triple-helix complexes are immobilized on streptavidin-coated magnetic beads, washed, and eluted with pH 9 buffer solution. The fragments are separated and directly sized by agarose gel electrophoresis. Bidirectional maps are obtained simultaneously by binding to the two different triple-helix-forming oligonucleotides. No probe labeling, gel drying, blotting to membranes, hybridization, or autoradiography is necessary. Also, TAC conditions that permit gel-free isolation of the terminal restriction fragments from cosmid inserts were found. These advantages afforded by ScosTriplex-II should facilitate the automation of cosmid restriction site fingerprinting needed for large-scale mapping and sequencing projects.

", pages = "185-192(8)", url = "http://www.ingentaconnect.com/content/ap/ge/1996/00000031/00000002/art00030" }