A Method of Fixing Rat Testis for Light and Electron Microscopy

To overcome the difficulty of obtaining compact slices or pieces of tissue from the rat testis, due to the scarcity of interstitial tissue, the fixation of the testis is started in the live anesthetized animal by injecting 3% glutaraldehyde in 0.1 M cacodylate buffer at pH 7.2 under the albuginea; within a few minutes this causes sufficient hardening of the testis tissue to enable one to cut neat slices from it with a razor blade. Fixation is completed with the usual immersion method. The fixed tissue may then be processed for either light or electron microscopy. Preservation of structural detail is comparable to that obtained with perfusion-fixation. The main advantages of the method are speed and simplicity, which may be very important when dealing simultaneously with several animals.