Genetic libraries

Probe A molecule used to detect the presence of a specific fragment of DNA or RNA in, for instance, a bacterial colony that is formed from a genetic library or during analysis by blot transfer techniques common probes are cDNA molecules, synthetic oligodeoxynucleotides of defined sequence, or antibodies to specific proteins. 

Genome Sequences Provide the Ultimate Genetic Libraries... 

Fig. 6.18. A flow chart for constructing genetic libraries using the bacteriophage expression vector Agtll (After Simpson et al., 1986.)...

Synthesis of Chemical Genetics Libraries New Organic Synthesis Approaches to the Discovery of Biological Activity... 

Zang X, Loke P, Kim J, Wojnoonski K, Kusdra L, Allison JP. A genetic library screen for signaling proteins that interact with phosphorylated T cell costimulatory receptors. Genomics 2006 88 841-845. 

Step 2 Gene isolation (three alternative methods) Nucleic acid triplet sequencing for amino acid sequence mRNA isolation, with reverse transcriptase and complementary DNA DNA probes from genetic library... 

In contrast to rational approaches, the directed evolution of enzymes is based on the search of useful functionalities in libraries randomly generated and on improvement by suitable and proper selection. The directed evolution combines two powerful and independent technologies methods for the generation of random genetic libraries and strategies for the selection of variant enzymes with the specific capabilities [499-503]. This process can result in biocatalysts with non-natural proprieties, since the proteins are expressed in recombinant cells decoupled from its biological functions and evolved under unusual conditions. One additional advantage is the possibility to tailor not only individual proteins, but also the whole biosynthetic and catabohc pathways [471]. 

Asp mentioned above and Lys Ser, which was introduced in order to remove a proteolytic cleavage site [39]. Thus, there were altogether four fixed amino acid replacements in addition to fhe randomized side chains. The mutagenized gene cassette was fhen inserted into an appropriate E. coli vector and a genetic library comprising 3.7x10 variants was prepared [40]. 

The logical problem in imagining a prehiotic DNA/protein world is determining which came first the genetic library to specify proteins or the enzymes that catalyze the formation of DNA RNA world appears to solve some of this dilemma since RNA is both informational and catalytic. However, RNA is very reactive and does not appear to be capable of synthesis and survival under prebiotic conditions. 

Khersonsky, S. M. and Chang, Y. T. 2004. Forward chemical genetics Library scaffold design. Comb. Chem. High-Throughput Screen. 7 645-52. 

Bird, R. C. and Smith, B. F. 2002. Genetic Library Construction and Screening Advanced Techniques and... 

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