A quick test for the simultaneous determination of intactness and concentration of spermatozoa

The fluorescence of ethidium bromide bound to the DNA of bull spermatozoa can be used for the estimation of intactness and concentration of spermatozoa of washed sperm samples. For the full permeability of the spermatozoal membrane for ethidium bromide digitonin is used in a concentration of 50 micrograms/ml. The fluorescence signals before and after digitonin treatment reflect the portion of cells with intact cellular membrane in the sample. The signal after addition of digitonin correlates to a high degree with the sperm concentration. The method exhibits a sufficient accuracy for the estimation of sperm quality. That applies for the reproducibility with individual ejaculates as well as for the correlation to other methods determining the intactness and sperm concentration. This simple single-step technique requires only about 2 X 10(7) spermatozoa corresponding to 10 to 20 microliters of an average bull ejaculate.