At the laboratory level this is rare, as most healthcare providers will not test the semen and sperm unless specifically requested or there is a strong suspicion of a pathology in one of these areas discovered during the medical history or during the physical examination. It tends to get a yellowish tint as a man ages.
The optimal sexual abstinence for semen sample obtaining is from 2—7 days. Vasectomy Vasectomy reversal Vasovasostomy Vasoepididymostomy. Wein AJ, et al.