FADING OF FEULGEN-STAINED BOVINE SPERMATOZOA

Photometric restudy of 120 Feulgen-stained bovine spermatozoa after an interim period of 30-38 days from their initial date of measurement clearly demonstrates a marked decolorization of the cells, depending on the particular lot of Feulgen reagent used. With an eight-month-old and often-used reagent, no fading occurred over a period of 38 days. Using a fresh reagent, made with the same batch and initial content of basic fuchsin as the above, a fading of 14.6% was observed in 30 days, and of 20.9% in 37 days. These findings clearly emphasize the need for greater control of the Feulgen reagent and reaction and for the caution that must be exercised in using long prepared Feulgen-stained material for quantitative purposes.