RESUMEN
The objective of the study was to determine interval values of biochemical parameters in the most commonly applied experimental model among different species, i.e. rats. Blood analysis of experimental animals is done in different research fields. They are important especially in experiments in pharmacology, pathophysiology, experimental surgery, toxicology and for monitoring experimental disorders in laboratory animals. In this paper, basic biochemical markers in the blood serum of Buffalo and Wistar rats are also compared in relation to the animals' age and sex. The values were obtained using the latest available measurement methods and the above-listed checkpoints were considered. The biochemical markers show variability between the particular groups of animals related to their age, sex, and strain. The obtained data may be used to create a model of interval values of biochemical parameters for the Buffalo and Wistar rat strains. This study is necessary to enhance our understanding on basic parameters in these animals which are often used in different medical experiments.