Tissues prepared for histological and similar investigations - using molecular sieve to adsorb residual water from hygroscopic or fat dissolving liquid before reuse

摘要

A process for removing water and/or grease from tissue specimens which are to be subjected to histological, histochemical, histo-autoradiographic and electron microscope investigations etc., and are to be embedded in sections of paraffin, plastics, methacrylate etc. consists of: subjecting the specimens first to a hygroscopic and/or grease-dissolving liquid with a boiling point lower than that of water, evaporating the resultant mixture of water and hygroscopic liquid, and condensing it to regenerate it, then recycling the condensed liquid for reuse. Before the condensed flow is reused, it passes through or over a molecular sieve-type material to adsorb any residues of water still contained in the condensed liquid. Pref., the molecular sieve material is heated to desorb it and regenerate it. Prefd. molecular sieve materials are synthetic zeolites (aluminium silicates of alkaline and/or alkaline earth metals). Preferred temperature for regenerating the sieve is 350-400 deg.C. Preferred pore diameter of the material is 2.5-4.5 Angstrom units. This process considerably increases the useful life of the liquid before it has to be completely replaced. For example, where acetone is used, its useful life is doubled.