Enhanced Chemiluminescence Assay vs Colorimetric Assay for Measurement of the Total Antioxidant Capacity of Human Seminal Plasma

Abstract

Although the enhanced chemiluminescence assay is commonly used to measure the nonenzymatic total antioxidant capacity (TAC) of the human seminal plasma, it is cumbersome, expensive, and time-consuming. We describe herein an alternate method to measure TAC that is based on the ability of antioxidants in seminal plasma to interfere with a reaction between 2,2'-azino-di-[3-ethylbenzthiazoline sulphonate] and metmyoglobin with H(2)O(2). This reaction produces a relatively stable blue-green color with absorbance maxima at 600 nm. We compared this colorimetric assay with our established chemiluminescence method and assessed quality control parameters (ie, intra-assay and interassay variabilities) in addition to intraobserver and interobserver differences. Our results show that the colorimetric assay was fairly predictive of antioxidant capacity similar to the chemiluminescence assay (P <.001). Furthermore, there was a high level of agreement between the duplicate measures by the same observer (intraobserver) and intra-assay variability, with a concordance correlation coefficient of 0.99. The interassay coefficient of variation was 4.7% (overall). The mean +/- SD of the difference between the 2 observers was 2.98% +/- 4.1%. In conclusion, we found that the colorimetric assay is a reliable and accurate method to evaluate seminal TAC, and it could be used as a simpler, rapid, and cheaper alternative to the chemiluminescence assay.

Antioxidant capacity of seminal plasma measured by TAS Randox®

“…The ECL method is highly sensitive, but expensive and also time-consuming for use in clinical practice. A satisfactory correlation, albeit on a very small sample size, between the ECL method and the manual colorimetric method based on the formation of the radical ions, ABTS + has been reported 13 . This method has been commercialized by Randox Ltd. as the TAS (Total Antioxidant Status) Randox ® kit.…”

The effects of three different exercise modalities on markers of male reproduction in healthy subjects: a randomized controlled trial

“…TAC was measured by colorimetric assay (Meucci et al 2003, Said et al 2003. We used commercially available colorimetric method (Randox Laboratories Ltd, UK).…”

Exercise modulation of total antioxidant capacity (TAC): towards a molecular signature of healthy aging

“…These methods are based on the time of induction of oxidation of a lipid dispersion exposed to the 2,2 -azo-bis (2-amidinepropane) (ABAP) in environmental temperature and the measurement of chemiluminescence intensity after sample incubation with luminol or luciferol (Whitehead et al 1992;Said et al 2003;Bastos et al 2006). Although Table 1 presents reference values for TAC, a very important recommendation is that each laboratory should maintain their own reference data, as gender, age, lifestyle variables, ethnic differences, genome diversity and other factors can change the antioxidant responses.…”