The histochemical localization of cholesterol in formalin-fixed and fresh frozen sections

The premixed cholesterol reagent (acetic acid, sulphuric acid, ferric chloride and phosphoric acid) employed in a spectrophotometric method for serum cholesterol determinations was applied to frozen sections of various rat and rabbit tissues. The histochemical reaction was compared with the results obtained by the classical Schultz reaction. The same bluish-green color was observed after treatment of formalin-fixed and fresh cryostat sections incubated in 2.5% iron alum at 37 C for 3 days. The premixed cholesterol reagent is stable for years at room temperature if stored in a brown bottle and is thus readily available for routine use.