Rapid and simple fixation-staining technique of fresh frozen cryostat sections for SIMS microscopy

Before observing freeze-dried cryosections by ion microscopy, it is necessary to perform localization of the analysis site by light microscopy. The present study reports a rapid fixation-staining method for preparing freeze-dried or air-dried cryosections, wherein cryosections are observed after immersion in Carnoy-Lebrun fixative for 30 s and staining in undiluted Giemsa solution for 30 s. Cryostat sections of goldfish intestine and kidney tissue on the silicon wafer substratum were subsequently examined by SIMS. Positive cesium ion images showed a general histology of the intestinal villi with goblet cells. Their granules contained large amounts of sodium, magnesium, potassium and calcium on ion images. By contrast, iron, copper and CsFe ion images showed diffuse distribution throughout the sections.