Sensitivity of picroindigocarmine/nuclear fast red (PIC/NF) stain for detection of spermatozoa: a serial dilution study of human ejaculate.

A serial dilution study from human ejaculate was done in order to assess the sensitivity of a commonly employed stain, picroindigocarmine/nuclear fast red, for the detection of spermatozoa. The results of the study indicate that spermatozoa may be detected readily at very low concentrations by scanning 20 high-power fields of a stained smear.