Bouin’s fixative solution is an effective, acidic, general fixative used with good results for gastro-intestinal and endocrinal biopsies and with exceptional results on specimens being prepared for trichrome staining. It preserves glycogen, but because of its acidity, will slowly breakdown iron and calcium intracellular deposits. The little picric acid in the solution turns specimens yellow, but this can be removed prior to staining by washing specimens with a solution of 70% ethanol in water. The fixation time is 4-18 hours, depending on the specimen. Smaller sizes sold in wide-mouth bottles to allow fixation directly in the bottles without decanting.