Resistance of Tritium Activity in Adenine - 2 , 8 - T Labelled Rabbit Sperm

Rabbit spermatozoa were labelled in vivo by injecting a male whith 6 mCi of 2,8-T-adenine. On day 49 after injection, a suspension of spermatozoa from caudae epididymidis and ductus deferentes in saline was prepared. Sperm samples were stored frozen at 5°C, exposed to autolysis for 10 days at + 37° C, and smeared. Smears from freshly obtained sperm were hydrolyzed with HCI iN or extracted with TCA (table i). All smears were coated with Kodak stripping film AR. io and the autoradiographs obtained were evaluated quantitatively. No marked difference was detected between fresh and frozen -!autolyzed sperm in grain number/sperm head. Graphical and statistical analyses confirmed the non-significance of differences. Accuracy of the autoradiographic method used is supposed to be sufficient to exclude considerable loss of activity from the sperm heads. (Standard deviation of repeated determination of mean grain count in the same slide amounts approximately to 5 per cent. On the contrary, complete loss of activity was detected in hydrolyzed and extracted smears. Presence of some activity in the autolysed sperm medium in a substance utilizable by bacteria was revealed in a few labelled bacterial colonies.