Preparing histological sections of non-decalcified bone compact - by impregnating with and embedding in methyl methacrylate, polymerising and sawing

Direct prodn. of 20-40 mu thick histological longitudinal and cross sections of non-decalcified bone compacts of man, dog, etc., is effected using Me methacrylate mixed with a catalyst and a plasticiser as impregnating and embedding compsn. for fixed and dehydrated and intermediately treated bone sample. Sections are cut with a micro-circular saw turning at 15000 rpm. The bone sample is first impregnated with Me methacrylate for >=24 hrs. at +4 degrees C. It is then re-impregnated with me methacrylate, mixed with 3-4% benzoyl peroxide and 20-30% nonylphenol-polyglycol ether acetate, at +4 degrees C. The twice-impregnated bone sample is then embedded in a mixt. contg. 4 g. benzoyl peroxide and 0.5 g. polyethylene glycol, having average mol. wt. 1500, for each 100 ml. Me methacrylate. Mixt. is first polymerised 30 mins. at 40 degrees C and left for further polymerisation at 37 degrees C. Block is finally sawn. Polymerised embedding mixt. is pref. further hardened at 60 degrees C, in a warming cabinet. The sections obtd. need no further polishing and can be dyed. Polymer blocks are free from blisters. Sepn. at bone-plastic surface and micro-fractures are prevented. Bone structure can be studied without using specific qualities of light.