Interpretation of laboratory test results from experimental subjects requires knowledge of results expected in a population of normal animals.
For the most accurate assessment the analytical values of the test animals should be compared to results from animals of the same species, age, gender and breed or strain obtained under environmental conditions approximating those of the experimental animals (ie a reference population).
The more closely the reference population reflects the composition and conditions of the experimental subjects, the more useful the reference interval.
Ideally, for statistical significance, a minimum of 160 animals of the species, breed, age and gender of experimental animals should be assayed. The conditions of the blood sampling should approximate the experimental setting. For example, if anesthetized animals are sampled during the experiment, the reference interval should be derived from anesthetized animals.
Results from the reference population are tabulated and assessed using statistical software (EP Evaluator) and the reference range established after assessment for outliers, review of parametric and nonparametric analysis of result distribution.
Reference Interval Development
Marshfield Labs can provide custom reference interval development for your research animals. Veterinary pathologists are available for consultation regarding the best approach for these studies and for guidance in result interpretation.