A method for preparing whole-body sections suitable for autoradiographic, histological and histochemical studies

A method for the preparation of whole-body sections suitable for autoradiographic and histochemical study is described. Radioactive calcium chloride or [14C]proline was injected into the abdominal cavity of a rat. Thirty-five minutes after injection of calcium chloride or 40 min after injection of proline the rat was frozen in a mixture of hexane and solid carbon dioxide and blocked in 5% sodium carboxymethyl cellulose. The carboxymethyl cellulose block was trimmed and a piece of copy paper was attached to the surface of the block with cellulose tape. Cryotome sections cut from the block were transferred from the paper to a glass slide coated with synthetic rubber adhesive. For whole-body autoradiography, sections were freeze-dried for 2 days and then placed against X-ray film. For light microscopic autoradiography, the freeze-dried sections were covered with a dried film of photographic emulsion. For histochemical use, the sections were fixed by raising the temperature to 4 C after immersion in 100% ethanol below -10 C. For histological observation, sections were postfixed with 2.5% glutaraldehyde and stained. Whole-body and light microscopic autoradiographs showed that sections so prepared could be used for the demonstration of soluble substances in whole-body sections and for detailed autoradiography at the light microscopic level, and the stained sections could be used for histological and histochemical studies.