Aldehyde-stabilized cryopreservation
Aldehyde-stabilized cryopreservation is a new technique for cryopreservation first demonstrated in 2016 by Robert L. McIntyre and Gregory Fahy at the cryobiology research company 21st Century Medicine, Inc. This technique uses a particular implementation of fixation and vitrification that can successfully preserve a rabbit brain in "near perfect" condition at −135 °C, with the cell membranes, synapses, and intracellular structures intact in electron micrographs.
Source: Wikipedia — Aldehyde-stabilized cryopreservation (CC BY-SA 4.0)