ENUMERATION OF SEMEN LEUKOCYTES BY FLUORESCENCE IN-SITU HYBRIDIZATIONTECHNIQUE

Aim - To determine whether the fluorescent in situ hybridisation techn ique (FISH) using a total human DNA genomic probe can be used to enume rate semen leucocytes. Methods - Semen samples from five donors were s ubjected to a mild KCL solution. These samples were then biotin labell ed under FISH conditions using a total human DNA genomic probe and the leucocyte counts were determined. To check the accuracy of the techni que a monoclonal antibody against the common leucocyte antigen CD45 [K C56(T-200)] sewed as a control. An isotypic control for [KC56(T-200)], the immunoglobulin [MsIgG1], served as a secondary control. Results - Semen leucocytes stained by the FISH technique were easily detected b ecause of their distinct bright yellow colour, while the sperm cells w ere red. The leucocyte count ranged from 0.5 to 4.9 x 10(6) per mi of semen. KC56(T-200) and its isotypic control MsIgG1, which served as co ntrol for the FISH technique, accurately identified 94% and 97% of the semen leucocytes of a control donor, respectively. Conclusions - The FISH technique using a total human DNA probe can accurately and effect ively enumerate the overall leucocyte population in semen.