(phage) n. a virus that attacks bacteria. In general, a phage consists of a head, tail, and tail fibres, all composed of protein molecules, and a core of DNA. The tail and tail fibres are responsible for attachment to the bacterial surface and for injection of the DNA core into the host cell. The phage grows and replicates in the bacterial cell, which is eventually destroyed with the release of new phages. Each phage acts specifically against a particular species of bacterium. This is utilized in phage typing, a technique of identifying bacteria by the action of known phages on them. See also lysogeny.
Subjects: Science and technology