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LUIZ F. ONUCHIC AND GREGORY G. GERMINO
the library releases more than one band. Chimerkclones isolated from partial digest libraries are much more difficult to detect. Careful comparison of
the restriction maps of the clone with the source DNA may yield clues, but
hybridization studies are often required to detect small, non-contiguous
fragments that are incorporated during packaging. If such end-fragments
remain undetected, the next chromosome walk will isolate a non-contiguous set of clones elsewhere in the genome, leading to a fatal mapping mistake.
Effort required to construct a representative library compared with the availability
of previously prepared libraries - considerations and recommendations
Unless one has specific requirements or has ample experience making libraries, the effort required to construct a genomic library in lambda bacteriophage or cosmids is considerable and may ultimately cost much more
in terms of time and money than purchasing a commerciallibrary. YAC and
Pl libraries are even more difficult to construct. A host of lambda bacteriophage and cosmid libraries are commercially available, and their quality
has greatly improved in recent years. A number of commercial and not-forprofit organizations offer YAC and Pllibrary screening, and gridded chromosome-specific libraries are also available from a number of sources ( eg.
Los Alamos National Laboratory, USA). There are, nevertheless, circumstances in which one may require a genomic library prepared from a specific
source ofDNA, such as when one wishes to clone a translocation breakpoint
associated with tumor formation in a particular cell type. Such "do-it-yourself' libraries usually are constructed using lambda bacteriophage as the
vector since this system is the most efficient and least tedious to prepare.
References
AusubelFM, Brent R, Kingston RE, Moore,DD SeidmanJG, SmithJA and Struhl K (1991)
Current Protocols in Molecular Biology, John Wiley and Sons. New York, New York
Meyerowitz EM, Guild GM, Prestidge LS and Hogness DS (1981) A new high-capacity
cosmid vector and its use. Gene 11:271282
Seed B, Parker RC and Davidson, N (1982) Representation ofDNA sequences in recombinant DNA libraries prepared by restriction enzyme partial digestion. Gene
19:201209
LUIZ F. ONUCHIC AND GREGORY G. GERMINO
the library releases more than one band. Chimerkclones isolated from partial digest libraries are much more difficult to detect. Careful comparison of
the restriction maps of the clone with the source DNA may yield clues, but
hybridization studies are often required to detect small, non-contiguous
fragments that are incorporated during packaging. If such end-fragments
remain undetected, the next chromosome walk will isolate a non-contiguous set of clones elsewhere in the genome, leading to a fatal mapping mistake.
Effort required to construct a representative library compared with the availability
of previously prepared libraries - considerations and recommendations
Unless one has specific requirements or has ample experience making libraries, the effort required to construct a genomic library in lambda bacteriophage or cosmids is considerable and may ultimately cost much more
in terms of time and money than purchasing a commerciallibrary. YAC and
Pl libraries are even more difficult to construct. A host of lambda bacteriophage and cosmid libraries are commercially available, and their quality
has greatly improved in recent years. A number of commercial and not-forprofit organizations offer YAC and Pllibrary screening, and gridded chromosome-specific libraries are also available from a number of sources ( eg.
Los Alamos National Laboratory, USA). There are, nevertheless, circumstances in which one may require a genomic library prepared from a specific
source ofDNA, such as when one wishes to clone a translocation breakpoint
associated with tumor formation in a particular cell type. Such "do-it-yourself' libraries usually are constructed using lambda bacteriophage as the
vector since this system is the most efficient and least tedious to prepare.
References
AusubelFM, Brent R, Kingston RE, Moore,DD SeidmanJG, SmithJA and Struhl K (1991)
Current Protocols in Molecular Biology, John Wiley and Sons. New York, New York
Meyerowitz EM, Guild GM, Prestidge LS and Hogness DS (1981) A new high-capacity
cosmid vector and its use. Gene 11:271282
Seed B, Parker RC and Davidson, N (1982) Representation ofDNA sequences in recombinant DNA libraries prepared by restriction enzyme partial digestion. Gene
19:201209