The staggered extension process (also referred to as StEP) is a common technique used in
biotechnology
Biotechnology is a multidisciplinary field that involves the integration of natural sciences and Engineering Science, engineering sciences in order to achieve the application of organisms and parts thereof for products and services. Specialists ...
and
molecular biology
Molecular biology is a branch of biology that seeks to understand the molecule, molecular basis of biological activity in and between Cell (biology), cells, including biomolecule, biomolecular synthesis, modification, mechanisms, and interactio ...
to create new, mutated genes with qualities of one or more initial genes.
The technique itself is a modified
polymerase chain reaction
The polymerase chain reaction (PCR) is a method widely used to make millions to billions of copies of a specific DNA sample rapidly, allowing scientists to amplify a very small sample of DNA (or a part of it) sufficiently to enable detailed st ...
with very short (approximately 10 seconds) cycles.
In these cycles the elongation of DNA is very quick (only a few hundred base pairs) and synthesized fragments anneal with complementary fragments of other strands. In this way, mutations of the initial genes are shuffled and in the end genes with new combinations of mutations are amplified.
The StEP protocol has been found to be useful as a method of
directed evolution for the discovery of enzymes useful to industry.
References
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Genetics
Molecular biology techniques