Application of 10-microm thin stainless foil to a new assembly of the specimen carrier in high-pressure freezing.

High-pressure freezing (HPF) has been accepted generally as the most reliable method for cryoimmobilization of biological samples. However, the depth of vitreous freezing in biological samples was less than expected, probably because of the poor thermal conductivity with high water contents. In this study, we introduce a new assembly of the specimen carrier using a 10-microm thin stainless foil for the specimen chamber cover in the HPF technique and describe the fine structure of rat gastric glands processed with the assembly. A low-magnification view of the gastric surface region showed a well-preserved morphology in which the vitreous freezing reached deeper than 100-microm from the freezing face. The present results prove that the 10-microm thin stainless foil is useful in HPF, providing deep vitrification in biological samples.