Examination of the accuracy of the quantitative in-house kit for determining zinc concentration in seminal fluid

Abstract

Zinc in seminal fluid originates primarily from the prostate gland. It is pivotal for male sexual function because it affects the quantity, quality and mobility of sperm. Materials and methods: the semen samples were obtained from 300 male partners of infertile couples who attended the Department of Biomedicine and Genetics at the Hanoi Medical University between the ages of 18 and 50 years; they were then analysed for routine seminal parameters. They were collected and analysed according to WHO 2010 guidelines. Seminal fluid was centrifuged at 1,500 rpm for 10 minutes, and floating fluid collected for zinc quantification using spectroscopy with 5-Br-PAPS was used as a color indicator. In a pH 8.6-buffer solution, in a buffered media, zinc reacts with specific complexing 5-Br-PAPS form a stable color compound. The optical density is directly proportional to the concentration of zinc in the semen. The results yielded a linear regression model of y = 0.0666x + 1.2026 with a correlation coefficient of r=0.9956. The calibration function was y = 0.9977x with R²=0.9995. The repeatability was SD=0.004, and the coefficient of variation was CV%=0.27%<5%. In terms of intermediate precision, the standard deviation was (SD)=0.01, and the coefficient of variation was CV%=0.64%<5%. Trueness was t_ex =2.076 < t_t=2.262. Specificity and sensitively were 100% at 64x dilution. Specificity and sensitivity were 100% and 99.05% respectively. A significant correlation was discovered between the two methods, with r=0.975 and p<0.001; the average difference between the two methods was 0.0002. Conclusion: successfully completed the kit for determining zinc concentration in semen by the colorimetric method.