[New fixative for pathological specimens in cold areas]

In cold areas where the lowest temperature of the day can fall to minus 20 degree Celsius in winter, surgical specimens which are sent from the local hospitals to the pathology department often become frozen during delivery. Although the antigenicity of tissues may remain intact, pathological diagnosis is difficult due to the destruction of the tissue by freezing. To overcome this difficulty and the development of artifact, we have attempted to make a fixative based on a 10% formalin solution to provide good fixation effect. Various mixtures of 10% formalin with sucrose, dimethyl sulfoxide (DMSO), glycerin, ethylene glycol and polyethylene glycol were prepared in different concentrations. Tissues of liver, kidney and stomach taken from autopsy or surgical biopsy were fixed with each solution at room temperature for 24 hours and then exposed to -20 degrees C for 2 days. After they were returned to room temperature, they were embedded in paraffin and stained with H&E and immunohistochemically examined by the PAP method. It could be shown that 10% formalin containing 20% ethylene glycol was the most suitable "fixative" to use. The specimens did not freeze and examination of the tissues showed that the morphology and antigenicity remained intact. In addition, this solution could be prepared easily and economically.