HISTOCHEMISTRY AND IMMUNOHISTOCHEMISTRY ON BONE-MARROW BIOPSIES - A RAPID PROCEDURE FOR METHYL-METHACRYLATE EMBEDDING

Starting from previous methodical approaches a procedure for low tempe rature methyl methacrylate (MMA) embedding of bone marrow biopsies is introduced which allows routine application of enzyme and immunohistoc hemistry without loss of morphological quality by retaining fixation i n Schaffer's solution. Survival of enzyme activity and antigen determi nants is achieved by washing the fixed specimens in 70% methanol and d ehydration in acetone in ascending concentrations at 4 degrees C. Modi fications of the plastic embedding technique used in this study simpli fy and shorten the procedure, so that embedding according to this rout ine method is complete after two days of preparation. Additionally, a rapid embedding variant is introduced, which enables tissue preparatio n within one day if necessary. Results are demonstrated using markers for myeloid, lymphoid and epithelial cells as well as immunoglobulins and the proliferation associated antigen Ki-67. The investigation of a panel of monoclonal and polyspecific antibodies in 31 cases shows the eventually reduced immunoreactivity of a few markers after prolonged fixation. As a consequence it seems essential to ensure shout fixation periods, especially when the specimens are sent by mail.