HOST - A cell whose metabolism is used for the expansion and reproduction of a virus, plasmid, or different type of international DNA. VECTOR - A plasmid, phage or cosmid into which overseas DNA may be inserted for cloning. OLIGONUCLEOTIDES - Short segments of DNA or RNA, i.e.; a series of a few 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 trusted amino acids manufacturer acids.