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.
