Clark’s fixative solution is an effective, acidic, general fixative used with a good result on smears and frozen sections. The fixation time is 3-4 hours, and the fixed specimen must not be left in the solution beyond that time, though the specimen may be transferred directly to 95% ethanol for longer storage. It preserves nucleic acids and dissolves lipids. Hempstead Halide sells smaller quantities in wide-mouth bottles to allow fixation directly in the bottle without decanting. Use all appropriate safety measures when working with Clark’s fixative solution. Refer to the relevant safety data sheet(s).