Total Antioxidant Capacity Determination with Colorimetric Method and Microplate Reading Format and Comparison with Chemilumin Essence Assay

Abstract

Total antioxidant capacity (TAC) is related to a variety of molecules that protect biological systems against reactive oxygen species (ROS). The importance of total antioxidants results in the requirement of TAC assay methods. This study is done to design a simple, rapid and inexpensive method for TAC measurement. In this method, ABTS (2, 2′-azino-bis [3-ethylbenzthiazoline-6-sulfonic acid]) was incubated with met myoglobin and H2O2 to produce green radical cation ABTS+. Antioxidants were suppressed the color production, thereby reducing the intensity of the color that was proportional to the concentration of antioxidants, measured at 600nm with a microplate reading format. Trolox was served as a standard or control antioxidant. Sensitivity, precision and accuracy were examined to check the validity of the method. Sensitivity of this method was 0.10 U/ml. The coefficient of variation percent for intra and inter assay was less than 9.6%. According to parallelism and recovery tests, ratio% and recovery% ranged from 90.9-108% and correlation coefficient in comparison with the sensitive chemiluminescence method was 0.9897 (n=60). Data from this study showed that this method has a good sensitivity, precision and accuracy and can be suitable for clinical and research uses.