comparison of reactive oxygen species in neat and washed semen of infertile men

background: male are involved in near 50% of cases of infertility and reactive oxygen species (ros) playing an important role in decreasing fertility potential. accurate measurement of ros seems to be important in evaluation of infertile male patients. objective: to compare ros measurement in neat and washed semen samples of infertile men and define the best method for evaluation of ros in these patients. materials and methods: we measured the level of ros in semen samples of thirty five non-azoospermic men with infertility. the semen samples were divided into two parts and the semen parameters and ros levels in neat and washed samples were evaluated. we also evaluated the presence of pyospermia using peroxidase test. results: the differences regarding sperm count and quick motility were significant in neat and washed semen samples. the mean ros level was significantly higher in neat samples compared with washed spermatozoa (7.50 rlu vs. 1.20 rlu respectively). difference in ros levels was more significant in patients with pyospermia compared to whom with no pyospermia (378.67 rlu vs. 9.48 rlu respectively). conclusion: our study confirmed that neat or unprocessed samples are better index of normal oxidative status of semen samples. because we do not artificially add or remove factors that may play an important role in oxidative equilibrium status.