A DNA molecule (plasmid, virus, bacteriophage, artificial or cut DNA molecule) capable of being replicated and bearing cloning sites for the introduction of foreign DNA, used to introduce this DNA into host cells.
Any organism that transmits a disease between two hosts.
PAC, 1992, 64, 143
(Glossary for chemists of terms used in biotechnology (IUPAC Recommendations 1992))
on page 168