ABSTRACT
To increase the accessibility of nucleic acids to a probe, embedding tissue can be avoided. In order to cut ultrathin sections, the tissue is hardened by freezing. The sections obtained by this method are referred to as ultrathin sections of frozen tissue. This chapter discusses cryoprotection and its principles. Cryoprotection limits the formation of crystals when tissue liquids freeze. Some molecules in solution become solid via an amorphous form (i.e., without crystallization). The chapter reviews different cryoprotective agents, cryogenic agents, freezing methods such as programmed freezing. Cryo-ultramicrotomy involves cutting ultrathin sections of frozen tissue. The chapter discusses deproteinization, oligonucleotide probes and hybridization protocols.
