CORTICOSTERONE ASSAY – ANALYTICAL METHOD VALIDATION FOR THE ANALYSIS OF CORTICOSTERONE IN RAT SERUM BY HPLC

T. Jyothi Kiran* and B. S. Ramakrishna

ABSTRACT

Plasma/serum corticosterone concentration is one of the most reliable physiological markers of ‘stress’since stress is characterized by elevated glucocorticoids. Most of the animal studies in behavioural research involve estimation of plasma/serum corticosterone levels along with behavioural assays. However a vast majority of these studies utilize the radio immuno assay technique which is quick and reliable but quite expensive. In this study, we demonstrate the validation of a method using high performance liquid chromatography coupled with a diode array detector for the determination of serum corticosterone concentrations which is a cost effective and reliable alternative to the routine radio immune assay. The linearity was done at a concentration range of 0 to 1000 ng/ml (R2=0.996).The percentage recovery was more than 90% and relative standard deviation was less than 8%. The limit of detection was 5ng/ml and limit of quantification was 10 ng/ml. This method has demonstrated reliability and can be used for the routine estimation of serum corticosterone levels for behavioural research.

Keywords: Stress, Corticosterone Assay, HPLC, Behavioural Research.