Study of the concentration of formic acid for decalcification of bone and the HE stain

Objective This study is to investigate the decalcification effect of different concentrations of formic acid solution and to determine the best one.Methods Bone tissues from 330 cases were dissected and equally and randomly divided into 3 shares.Each was immersed in the formic acid of 40%,30% and 20% concentration for 24 h separately.Then the efficiency of cutting section and the HE stain were evaluated.Result With all three concentrations of formic acid solution,the sections were cut smoothly and completely in all the groups except the 20% concentration group.The HE stain of some cases from 20% concentration groups was pale in the stain of the nuclei and the cytoplasm.The HE stain of some cases from 40% concentration groups was pale in the stain of the nuclei and reddish in the cytoplasm.Both the nuclei and cytoplasm were stained well in the groups of 30% concentration.Conclusion The slides of bone tissue should be kept intact and well stained.So,in our study,the best choice is the formic acid of 30% concentration. Key words: Bone tissue; Formic acid-decalcification solution; Concentration