A rapid method to identify cosmids containing rare restriction site

Xavier P. Estivill, R. Williamson

Research output: Contribution to journalArticle

15 Citations (Scopus)


A procedure for identifying specific cosmid clones containing recognition sites for "rare cutting" restriction enzymes has been developed. Cosmid clones containing human inserts were selected by hybridisation to human repetitive DNA. An oligonucleotide corresponding to the NotI recognition site, eight bases long, was labelled and used to probe DNA samples from one hundred cosmids. By optimising the difference in melting characteristics between eight-base perfect match and six-base match/two base mismatch hybrids, we were able to detect the cosmids containing either NotI (8 bp match) or XmaIII/EagI (6 bp match) sites. The generation of a map for rare cutter sites along a human chromosome, or a chromosome region, should be simplified using this approach, which will enable the identification of a set of "milestones" at intervals of several hundred kilobases (kb) along the DNA sequence.

Original languageEnglish
Pages (from-to)1415-1425
Number of pages11
JournalNucleic Acids Research
Issue number4
Publication statusPublished - 25 Feb 1987
Externally publishedYes


ASJC Scopus subject areas

  • Genetics

Cite this