High pressure freezing comes of age.

TLDR

High‑pressure freezing enables cryo‑immobilization of thick biological specimens up to about 500 µm. The high yield is achieved by optimizing pressure and temperature transfer through replacing specimen water or buffer with low‑viscosity, low‑surface‑tension 1‑hexadecene. Using this method, suspensions of microorganisms, plant, and animal tissue yield a very high proportion of adequately frozen specimens with no ice‑crystal segregation after freeze‑substitution or freeze‑fracturing.

Abstract

High pressure freezing permits the successful cryoimmobilization of thick biological specimens (up to approx. 500 microns). A very high yield of adequately frozen specimens, in which no segregation patterns due to ice crystal formation is apparent after freeze-substitution or freeze-fracturing, is obtained with suspensions of microorganisms as well as plant and animal tissue. This very high yield is attributed to an optimized transfer of pressure and cold to the biological specimen. This is achieved by replacement of extraspecimen water or buffer by 1-hexadecene, a chemically inert, hydrophobic paraffin oil of low viscosity and low surface tension.