Freeze‐etching of unglycerinated tissue dispersions by application of the oil emulsion technique

Abstract

The oil emulsion technique was applied to rat brain and liver tissue for freeze-etching preparation without antifreeze pretreatment. The dispersed tissue exhibited a high degree of vitrification throughout the mostly globular fragments up to at least 30 .mu.m in diameter. Signs of insignificant ice crystal formation of 50 nm and less was only rarely detected. Although the dispersion process seriously affected the tissue organization as a whole, most cellular organelles and the plasma membrane showed satisfactory preservation of structure. In larger tissue drops, a local overall structural preservation of the original cellular organization was recognizable. This method is applicable to various biological objects for realizing sufficient cryofixation in the absence of cryoprotectorants.