Health Dictionary
Reliable, easy-to-read patient information on common medical conditions β written in plain language, free of jargon, and grounded in current evidence. Browse the most frequent diagnoses, understand what they mean for everyday life, and learn which steps and questions help you have a focused conversation with your doctor.
Strain
Introduction
In biology, strain is used in three related ways.
Microbiology/Virology
A strain is a genetic variant or subtype of a virus or bacterium. For example, a “flu strain” is a certain biological form of the influenza or “flu” virus. Compare clade.
Plants
A strain is a group of plants with similar (but not identical) appearance and/or properties. The term has no official status. See cultivar.
Rodents
A mouse or a rat strain is a group of animals that is genetically uniform. Strains are used in laboratory experiments. Mouse strains can be inbred, mutated or genetically engineered, while rat strains are usually inbred.