Table 2.

Advantages and disadvantages of indirect measurement of ROS in semen.

Assays	Advantages	Disadvantages
Myeloperoxidase or Endtz test [9]	Clearly distinguishes WBCs especially ROS producing granuloctyes from other immature germ cells in semen	Cannot be used to detect ROS generation by spermatozoa
Lipid peroxidation levels [8]	Malondialdehyde is a coloured substance that can be measured by fluorometry or spectrophotometry Low sperm concentration of malondialdehyde can be measured through sensitive HPLC equipment or spectrofluorometric measurement of iron-based promoters	Not widely used in clinical practice at this time
Chemokines [14], [15]	Produced as a result of ROS induced inflammation	Requires a large amount of biological material (>0.5 L of culture supernatants)
Antioxidants, micronutrients, vitamins (vitamin E, vitamin C) [8]	Cofactor of essential enzymatic reactions of ROS	Assesses an end state occurring secondary to other unknown pathological processes.
Antioxidants – TAC [16], [17]	Rapid colorimetric method Total antioxidants in seminal plasma measured	Does not measure enzymatic antioxidants, or individual antioxidants Requires expensive assay kit and microplate reader.
DNA damage [18], [19]	Robust and sensitive method Multiple methods are available to measure DNA fragmentation such as sperm chromatin structure assay (SCSA), sperm chromatin dispersion, TUNEL, comet, sperm chromatin dispersion assay, nuclear protein composition, sperm nuclear maturity test, and 8-OHdG	Accessibility of the DNA Inter-observer, intra-observer + inter-assay and intra-assay variability. Lack of standardised reference Technique itself (i.e. 8-OHdG) has potential to cause DNA oxidation, which will interfere with the basal level

WBC, white blood cell; 8-OHdG, 8-hydroxy-2′-deoxyguanosine.