A rapid and easy technique for the simultaneous demonstration of lipids and starch in the same histological section is described. Tissues are prepared by the classical fixing and Araldite M embedding techniques of electron microscopy. Semithin sections are directly stained for 1 hour at 60C with saturated Sudan black B in 70% ethanol without removing the embedding resin. Lipids stain black; starch is shown as white grains contrasting with the blue-grey embedding resin.