Use of short oligonucleotides to screen cosmid libraries for clones containing G/C-rich sequences.
We have developed a method to identify clones containing recognition sequences for enzymes that cut mammalian genomes infrequently by direct screening of genomic libraries. The degenerate oligonucleotide NNGCGGCCGCNN, in which the internal 8 bases correspond to the recognition sequence of Not I, was used to screen a cosmid library, and it led to a greater than 10-fold enrichment in the number of clones containing Not I sites. This technique permits the efficient identification of sufficient clones from a chromosome-specific library to allow the construction of a complete pulsed-field map of that chromosome and to assist in finding genes in genomic DNA.
Research Institute, Hospital for Sick Children, Toronto, Ontario, Canada.
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D001483:Base Sequence; D003360:Cosmids / Q000235:genetics*; D003596:Cytosine; D015252:Deoxyribonucleases, Type II Site-Specific; D015723:Gene Library; D005821:Genetic Techniques; D006151:Guanosine; D008969:Molecular Sequence Data; D015345:Oligonucleotide Probes; D015183:Restriction Mapping
D015345:Oligonucleotide Probes; D006151:Guanosine; D003596:Cytosine; D015252:Deoxyribonucleases, Type II Site-Specific; C038565:GCGGCCGC-specific type II deoxyribonucleases