Abstract
A method which allows the observation of identical tissue components with both the light and electron microscopes is presented. The technique is based on the preparation of cryostat sections of organs with dimethylsulfoxide. This agent appears to prevent the damage to fine structure caused by freezing and thawing. The use of plastic sheets permits flat embedding of organ sections in Epon. Examination of the embedded sections, stained or unstained, in the light microscope allows the exact selection of material to be studied further in the electron microscope.