Preservation of glycogen in decalcified hard tissues

Summary Various fixatives and fixation procedures were tested to evaluate their effects on the preservation of glycogen in sections of decalcified hard tissues. Lower jaws from 1-day-old rats were chosen for the observations. An aqueous solution of glutaraldehyde showed poor preservation of glycogen in the tissues even when employed in the perfusion procedure. Freeze-drying and formaldehyde vapour fixation preserved it much better, but glycogen was still lost to some extent. Freeze-substitution with acetone and various alcoholic fixatives gave a poor result, unless the tissues were fixed with cyanuric chloride. Cyanuric chloride in methanol containing N-methyl morphorine was the best fixative for the preservation of glycogen in the sections. A combination of freeze-substitution with the cyanuric chloride solution, decalcification with the Jenkins's fluid, and subsequent double-embedding in celloidin and paraffin was recommendable for an excellent glycogen preservation.