HOST - A cell whose metabolism is used for the growth and reproduction of a virus, plasmid, or different form of overseas DNA. VECTOR - A plasmid, phage or cosmid into which international DNA could also be inserted for cloning. OLIGONUCLEOTIDES - Short segments of DNA or RNA, i.e.; a sequence of some nucleotides. NICK TRANSLATION - In vitro method used to introduce radioactively labelled nucleotides into DNA. REVERSE TRANSCRIPTASE - An enzyme that catalyzes the synthesis of DNA from RNA. RNA POLYMERASE - An enzyme that catalyzes the synthesis of RNA in transcription. A small molecule which interacts with a regulator protein and triggers gene transcription. PROTEIN - A polypeptide consisting of amino acids supplier for food industry acids.