2
I
I
Some
unknown virus is
is isolated from
severcelly
Patient. If want to make
genomic library of some Unknown
virus for sequencing purpose which
cloning vector
need
consider
for
work? write
the
detail
Procedure for generation
genomic
library for the same. (size of fragments
are
approximutely 11kb.
Answers
Most DNA cloning is done with E. coli plasmid vectors because of the relative simplicity of the cloning procedure. However, the number of individual clones that can be obtained by plasmid cloning is limited by the relatively low efficiency of E. coli transformation and the small number (only a few hundred) of individual transformed colonies that can be grown on a typical culture plate. These limitations make plasmid cloning of all the genomic DNA of higher organisms impractical. For example, ≈1.5 × 105 clones carrying 20-kb DNA fragments are required to represent the total human haploid genome, which contains ≈3 × 109 base pairs. Fortunately, cloning vectors derived from various bacteriophages have proved to be a practical means for obtaining the required number of clones to represent large genomes. A collection of clones that includes all the DNA sequences of a given species is called a genomic DNA library, or simply genomic library. Once a genomic library is prepared, it can be screened for clones containing a sequence of interest.