I expect that as many as half of the patients now in suspension were suspended without cryoprotective perfusion. Pretend that cryoprotectants were used and do the usual slow freeze. The result is hamburger. Cryoprotectants can rapidly diffuse into thin slices of tissue, thus preserving them well when they are frozen. The result is a Dagwood sandwich.
Microwaves can rapidly penetrate and fix tissue.
Pack the brain with ice and place in a microwave. Cook until well done. Treat brain with cryoprotectants by storing it in a concentrated cryoprotectant solution for a week. Store in freezer until needed. Freeze brain at -1 C to limit ice crystal damage.