How to Perform “IVCT”

Abstract

The isopentane-propane (IP) cryogen (−193 °C) was manually poured over exposed animal organs by the original in vivo cryotechnique (IVCT), which were simultaneously cryocut with a precooled cryoknife in liquid nitrogen (−196 °C) with a group of three persons. The in vivo frozen animal organs were cracked off from the animal body in the liquid nitrogen and then plunged into the liquid nitrogen. To perform the IVCT more easily, the “in vivo cryoapparatus” has been commercially available all over the world. The IVCT was originally performed with a handmade “in vivo cryoapparatus.” The operation manual about the new “in vivo cryoapparatus” is briefly described in this chapter. When the IVCT is used only for light microscopic observation, it can be more simply performed without any special cryoapparatus. So the simple “in vivo” freezing method is performed only by pouring the IP cryogen (−193 °C) directly onto living animal organs. This simple cryoprocedure usually allows us to make an easy performance of IVCT at a light microscopic level. In the prepared such specimens, good morphological preservation is within less than a few hundred micrometers away from the frozen tissue surface at a light microscopic level. The procedures to prepare the mixed isopentane-propane cryogen were described in this chapter.