Table 1. Advantages and disadvantages of commonly used techniques to measure seminal oxidative stress.
| Assay | Advantages | Disadvantages |
|---|---|---|
| ROS by chemiluminescence | • Chemiluminescence is robust | • Time-consuming method |
| • High sensitivity and specificity | • Requires large and expensive equipment | |
| • Luminol measures global ROS levels – both extracellular and intracellular (superoxide anion, hydrogen peroxide, hydroxyl radical) | • Variables such as semen age, volume, repeated centrifugation, temperature control and background luminescence may interfere with measurement | |
| TAC | • Rapid colorimetric method | • Does not measure enzymatic antioxidants |
| • Measures total antioxidants in seminal plasma | • Length of inhibition time is a critical aspect of the test | |
| • Requires expensive microplate readers | ||
| ROS-TAC score | • Better predictor compared with ROS or TAC alone | • Requires statistical modeling |
| • Not a direct measure of ROS or TAC, rather a prediction of oxidative stress | ||
| MDA-TBA adduct detection by colorimetry or fluoroscopy | • Measures lipid peroxidation | • Rigorous controls required |
| • Detects MDA-TBA adduct by colorimetry or fluoroscopy | • Non-specific test providing post hoc measure only | |
| ORP | • Provides redox balance in real time | • Affected by viscosity of the sample |
| • Measures all known and unknown oxidants and antioxidants | ||
| • Less time-consuming and requires less expertise | ||
| • Can be measured in semen and seminal plasma, including frozen specimens |
ROS: reactive oxygen species, TAC: total antioxidant capacity, MDA: malondialdehyde, TBA: thiobarbituric acid, ORP: oxidation-reduction potential. Data from Agarwal et al (Ther Adv Urol 2016;8:302-18) [76].