26-08-2017, 10:41 AM
The cDNA cloning process creates many double-stranded DNA fragments. By the nature of reverse transcriptase, the cloning process frequently aborts, creating DNA fragments that represent only part of the gene. This makes it difficult to obtain a highly representative large copy number cDNA library. From the cDNA construct it is possible to identify particular cDNA clones. This is useful in DNA sequencing, giving a researcher the ability to predict an amino acid sequence and eventual protein. The genomic sequence can be identified, allowing specific regions of gene control to be located. Hybridization assays can be performed, allowing the identification of transcriptional changes between normal and mutated regions of DNA sequences. Learn more about centers like CD Genomics, who are experts in dna & amp; genome, health diagnostics, bioinformatics, development of custom cdna libraries.
A genomic library is a collection of total genomic DNA from a single organism. The DNA is stored in a population of identical vectors, each containing a different DNA insert. In order to construct a genomic library, the organism's DNA is extracted from the cells and then digested with a restriction enzyme to cut the DNA into fragments of a specific size. The fragments are then inserted into the vector using DNA ligase. The vector DNA can then be absorbed by a host organism, commonly a population of Escherichia coli or yeast, with each cell containing only one vector molecule. The use of a host cell to carry the vector allows easy amplification and retrieval of specific clones from the library for analysis.
A cDNA library is a combination of cloned cDNA fragments (complementary DNA) inserted into a collection of host cells, which together constitute a part of the organ transcriptome and are stored as a "library". The cDNA is produced from fully transcribed mRNA found in the nucleus and therefore contains only the expressed genes of an organism. Similarly, tissue-specific cDNA libraries can be produced. In eukaryotic cells mature mRNA is already spliced, therefore the cDNA produced lacks introns and can be readily expressed in a bacterial cell. Although information in cDNA libraries is a powerful and useful tool since gene products are easily identified, libraries lack information on enhancers, introns and other regulatory elements found in a genomic DNA library.
A genomic library is a collection of total genomic DNA from a single organism. The DNA is stored in a population of identical vectors, each containing a different DNA insert. In order to construct a genomic library, the organism's DNA is extracted from the cells and then digested with a restriction enzyme to cut the DNA into fragments of a specific size. The fragments are then inserted into the vector using DNA ligase. The vector DNA can then be absorbed by a host organism, commonly a population of Escherichia coli or yeast, with each cell containing only one vector molecule. The use of a host cell to carry the vector allows easy amplification and retrieval of specific clones from the library for analysis.
A cDNA library is a combination of cloned cDNA fragments (complementary DNA) inserted into a collection of host cells, which together constitute a part of the organ transcriptome and are stored as a "library". The cDNA is produced from fully transcribed mRNA found in the nucleus and therefore contains only the expressed genes of an organism. Similarly, tissue-specific cDNA libraries can be produced. In eukaryotic cells mature mRNA is already spliced, therefore the cDNA produced lacks introns and can be readily expressed in a bacterial cell. Although information in cDNA libraries is a powerful and useful tool since gene products are easily identified, libraries lack information on enhancers, introns and other regulatory elements found in a genomic DNA library.