[Effect of prolonging time for sampling on preservation of ultrastructure during the specimen preparation].

The ultrastructural change of rat liver, which was not immediately fixed after separation from the animal, was observed under electron microscope. The results showed that the ultrastructure of hepatocytes still satisfied the needs for diagnostic electron microscopy if the isolated livers were soaked in normal saline for 30 minutes, at room temperature, or placed in 4 degrees C refrigerator for 60 minutes, then they were fixed. After the isolated samples were put at room temperature for over 30 minutes, ultrastructure of hepatocytes were damaged so severely as to lose value for observation under electron microscope.