"Mark" - what is it, definition of the term
The term denotes a symbolic indicator applied to an object or organism to convey identity, status, or measurement; in experimental work with rodents such as rats and mice, such indicators can be physical tags, colored dyes, or genetic labels that enable researchers to track individual subjects, differentiate experimental groups, and record observations reliably.
Detailed information
The term refers to any visual or genetic indicator used to differentiate individual rodents in scientific and laboratory settings. Physical indicators include ear notches, tattoo markings, and subcutaneous microchips. Each method provides a permanent or semi‑permanent means of recognition without affecting the animal’s health.
Genetic indicators consist of specific DNA sequences that can be detected through polymerase chain reaction (PCR) or sequencing. These markers enable researchers to track inheritance patterns, confirm breeding lines, and verify the presence of transgenes.
Common applications:
- Identification of breeding colonies to maintain genetic integrity.
- Monitoring of experimental groups to ensure accurate data collection.
- Tracing of disease transmission pathways in epidemiological studies.
Selection of an appropriate indicator depends on factors such as duration of the study, required precision, and ethical considerations. Physical tags are suitable for short‑term projects, while genetic markers are preferred for long‑term lineage tracking.