Preparing Specimens of Bone and Teeth for Cutting by the Paraffin Method

A method of preparing bone or teeth for sectioning is described which involves the following steps: 48 hr. in 1:10 formalin; 24 hr. in 70% alcohol; decalcification for several days in 10% HNO₃; rinsing and transferring to 2% potassium alum for 12 hr.; rinsing and treating with 5% NaHCO₃ (or Li₂CO₃) for 24 hr.; washing for 12-24 hr.; then passing through ascending grades of alcohol to xylene. In the case of developing teeth, a slightly different procedure is recommended: fixation in Heidenhain's Susa till hard tissue is decalcified; 24 hr. in 96% alcohol (with three changes); 24 hr. in absolute alcohol (with one change); clearing in xylene or chloroform, and embedding in paraffin.