How should a rat be chosen? - briefly
Choose a rat that is healthy, disease‑free, and of a standard laboratory strain appropriate to the experimental objectives. Ensure the animal’s age falls within the range required for the specific study design.
How should a rat be chosen? - in detail
When selecting a rat for experimental or breeding purposes, evaluate the animal against a set of objective criteria. Begin with genetic background: choose a strain that aligns with the study’s objectives, such as Sprague‑Dawley for toxicology or Wistar for behavioral research. Confirm that the lineage is documented and that the colony maintains genetic integrity.
Consider age and developmental stage. For most protocols, young adults (8–12 weeks) provide stable physiology and predictable growth rates. Record the exact post‑natal day to ensure reproducibility across trials.
Sex influences hormonal profiles and behavior. Decide whether males, females, or both are required, and verify that sex determination is accurate. If the experiment is sensitive to estrous cycles, synchronize or control for cycle stage.
Health status must be pristine. Source animals from an accredited vendor that supplies specific‑pathogen‑free (SPF) colonies. Perform a health screen that includes serology for common rodent viruses, bacterial cultures, and parasitology. Exclude individuals showing signs of illness, abnormal weight, or impaired locomotion.
Acclimatization is essential for reliable data. House rats in a controlled environment (temperature 20‑24 °C, humidity 40‑60 %, 12‑hour light/dark cycle) for at least one week before use. Provide enrichment and monitor behavior to detect stress indicators.
Documentation completes the selection process. Record strain, source, birth date, sex, health certifications, and cage conditions in a laboratory information management system (LIMS). Ensure traceability from procurement to experimental endpoint.
By systematically applying these parameters—genetics, age, sex, health, environment, and record‑keeping—researchers can reliably choose rats that meet experimental requirements while maintaining ethical standards.