- A molecule (as a short strand of RNA or DNA) whose presence is required for formation of another molecule (as a longer chain of DNA).
Definition from: Merriam-Webster's Medical Dictionary by Merriam-Webster Inc.
- Short preexisting polynucleotide chain to which new deoxyribonucleotides can be added by DNA polymerase.
Definition from: Human Genome Project Information
at the U.S. Department of Energy
- A primer is a short, single-stranded DNA sequence used in the polymerase chain reaction (PCR) technique. In the PCR method, a pair of primers is used to hybridize with the sample DNA and define the region of the DNA that will be amplified. Primers are also referred to as oligonucleotides.
Definition from: Talking Glossary of Genetic Terms from the National Human Genome Research Institute
Related discussion in the Handbook
See also Understanding Medical Terminology.