In molecular biology, a cDNA library refers to a complete, or nearly complete, set of all the mRNAs contained within a cell or organism. Because working with mRNA is difficult, researchers use an enzyme called reverse transcriptase which will produce a DNA copy of each mRNA strand. Referred to as cDNA these reverse transcribed mRNAs are collectively known as the library. Molecular biology is the study of biology at a molecular level. ... The interaction of mRNA in a eukaryote cell. ... In biochemistry, reverse transcriptase (EC 2. ... In genetics, complementary DNA (cDNA) is single-stranded DNA synthesized from a mature mRNA template. ...

Such a library has several uses. A cDNA of an eukaryotic organism (for example, a human) can be cloned into a prokaryotic organism (for example, E. coli) and expressed (translated into the appropriate protein) there (with limitations, for example posttranslational modification). A cDNA library is also important for analysis through bioinformatics. The complete cDNA library of an organism gives the total of the proteins it can possibly express. Also, the cDNA sequence gives the genetic relationship between organisms through the similarity of their cDNA. Kingdoms Animalia - Animals Fungi Plantae - Plants Protista A eukaryote (also spelled eucaryote) is an organism with complex cells, in which the genetic material is organized into membrane-bound nuclei. ... Cloning is the process of creating an identical copy of an original. ... Prokaryotes (from Old Greek pro- before + karyon nut, referring to the cell nucleus, + suffix -otos, pl. ... Binomial name Escherichia coli T. Escherich, 1885 Escherichia coli (usually abbreviated to E. coli) is one of the main species of bacteria that live in the lower intestines of warm-blooded animals (including birds and mammals) and are necessary for the proper digestion of food. ... Translation is the second process of protein biosynthesis (part of the overall process of gene expression). ... A representation of the 3D structure of myoglobin, showing coloured alpha helices. ... Posttranslational modification means the chemical modification of a protein after its translation. ... Bioinformatics or Computational Biology is the use of techniques from applied mathematics, informatics, statistics, and computer science to solve biological problems. ...

cDNA Library Construction

A cDNA library may originate from many sources. For example a researcher may be interested in what mRNAs are present in the embryo of an organism, thus they would produce a cDNA library from only embryo tissue. This cDNA library could then be used as a probe for DNA microarrays or as a clonal inserts into bacteria chromosomes. Often researchers will compare the mRNA profile from different tissues or developmental stages to determine genetic differences. Embryos (and one tadpole) of the wrinkled frog (Rana rugosa). ... A DNA microarray (also DNA chip or gene chip in common speech) is a piece of glass or plastic on which pieces of DNA have been affixed in a microscopic array. ... Figure 1: Chromosome. ... Embryogenesis is the process by which the embryo is formed and develops. ...

full-length cDNA libraries

Differently than standard cDNA libraries, in full-length cDNA libraries most of the cDNA represent complete original mRNA molecules. These are produced by implementation of normal methods for cDNA libraries preparation. The main technologies are known as "cap-trapper" and "oligo-capping".

External links

• Functional Annotation of the Mouse database

See also

Genomic library In molecular biology, a library is a collection of molecules in a stable form that represents some aspect of an organism. ...