insertional inactivation

in·ser·tion·al in·ac·ti·va·tion

a technique of recombinant DNA technology used to select bacteria that carry recombinant plasmids; a fragment of foreign DNA is inserted into a restriction site within a gene for antibiotic resistance, thus causing that gene to become nonfunctional.

insertional inactivation

insertion of a piece of DNA into the coding sequence of a GENE, which is thereby inactivated. It is often used to identify recombinant VECTORS (2) in GENE CLONING and in turn to distinguish a recombinant vector from a non-recombinant vector. For example, insertion of a piece of foreign DNA into a cloning site which is located on an antibiotic-resistant gene on the vector can lead to loss of the antibiotic resistance PHENOTYPE by insertional inactivation. The recombinant vector will therefore specify antibiotic sensitivity, whilst the non-recombinant vector will specify antibiotic resistance.

insertional

pertaining to

1. surgical or reproductive manipulation

2. molecular biological manipulation.

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insertional activity

the electrical tracing produced in electromyography as a result of the insertion of the needle electrode.

insertional inactivation

in recombinant DNA technology, an early method for selecting ampicillin (amp+) and tetracycline (tet+) resistant Escherichia coli transformed with plasmids such as pBR 322; foreign DNA was cloned into the tet gene, thereby disrupting the gene and rendering the cell tet⁻, which enabled selection when cells were plated onto amp and tet plates.