THE NEW HANNOVER METHOD FOR PLASTIC EMBED DING OF BONE-MARROW BIOPSIES - LOW-TEMPERATURE POLYMERIZATION OF METHYL-METHACRYLATE

A patented low-temperature polymerization method for methylmethacrylat e (MMA) infiltrated bone marrow biopsies is described: it has been dev eloped from our previous MMA technique and is a patented procedure. Di fferences from the previous method are (1)removal of stabilizer from t he MMA monomer before its application, (2) the use of a different star ter, (3) avoidance of O-2 influence during polymerization by means of vacuum exchange with N-2, and (4) polymerisation in a water bath to dr aw off residual heat. After this procedure, all immunohistochemical re actions are possible provided that the previous fixation is adequate. The effects of different fixatives are reviewed briefly without detail ed analysis. Technically, this plastic embedding can be performed at l east as rapidly as the das sic paraffin embedding after decalcificatio n. The advantages over the latter method are: (1) the cells can be bet ter differentiated because semi-thin sections can be made; (2) the imm unoreactions can also be performed on the basis of semithin sections, which means they can be interpreted more easily; (3) morphometric anal yses yield more reliable results because of the constant thickness of sections; (4) osteological examination of bone trabeculae, especially the search for mineralisation deficiencies, is possible; (5) the plast ic embedding procedure is less dependent on individual instabilities i n the quality of performance of the staff members involved. Furthermor e, it is worth mentioning that the costs for additional equipment nece ssary remain below DM 100,000 including an excellent microtome.