The preferential removal of bone and tooth collagen


  • Supported in part by P.H.S. Grant no. DE-01785-01 from the National Institutes of Health and General Research Grant no. 1-GS-15 U.S. Public Health Service.


This investigation was undertaken to remove collagen from bone and tooth sections following fixation, decalcification and sectioning so that the noncollagenous tissues could be better demonstrated. Half heads of white mice were fixed in one of the following:Susa, neutral buffered formalin, ethyl or methyl alcohols. Decalcification was carried out with formic acid-sodium citrate solution, hydrochloricformic acid mixtures, formic acid alone, or the tetrasodium salt of ethylenediamine tetra-acetic acid. Paraffin sections were cut at 8 μ. After deparaffinization and hydrations the sections were immersed in one of two solutions, distilled water alone or 0.1% solutionof collagenase in distilled water. The experimental sections were incubated at 37°Cfor periods ranging from two to four days. Sections were then stained with picro naphthol blue black, hematoxylin and eosin, Van Gieson's stain or Masson's stain. The distilled water sections showed no change. The collagenase treated sections showed that the collagen had been removed from the matrix of bone and dentin leaving behind theosteocytes and odontoblast processes.