Nowadays, In the medical field, they used to using brains for medical research. They need a fresh brain that has to arrive in 24 hours after died at least. Jorge Tejada and his team had found effectively frozen brain. The process takes about 17 hours since the moment of death until arriving at McLean Hospital and have to be removed intact and transported rapidly.
First, a brain is weighed, after that then sliced in half rinsed in sterile saline. There are two different way treatments. A half brain sliced from front to back and the cerebellum (key structure) removed. The slices placed into two plates and directly frozen using a cocktail of dry ice and liquid nitrogen. This way aims to minimize tissue damage. The frozen slices are then saved into deep freeze until needed. The other hemisphere is treated for examining and dissect needs. The hemisphere is soaked in formalin for few weeks.