I have infection in my semen. urine is clear. i'm going for std's screening.but laboratory requires urine or swab for specimen.can you tell me if i give urine sample it will detect bacteria or virus in semen? they do not perform these test from semen?

Urine or urethral swab testing will detect any STDs that might be present; negative results will rule them out as causes of your semen problem. Available STD testing includes nucleic acid (DNA or RNA) tests for gonorrhea, chlamydia, Mycoplasma genitalium and Trichomonas vaginalis. No viral STD could cause semen infection, so probably no need to test for HSV, HPV or any other virus.