title: Mitotic activity and delay in fixation of tumour tissue. The influence of delay in fixation on mitotic activity of a human osteogenic sarcoma grown in athymic nude mice.
abstract: The purpose of the present investigation was to study the effect of delay in fixation on the mitotic activity in tumour tissue. A human osteogenic sarcoma, especially suitable for counting of mitoses, grown in athymic nude mice, was fixed with varying delay and the mitotic, prophase, metaphase and ana-telophase indices were determined. An almost exponential decline of the mitotic index was observed with a reduction to 49.4% and 15.0% after respectively 60 and 180 minutes. The proportional incidence of prophases, metaphases and ana-telophases changed so that a relative accummulation of advanced phases occured during the 180 minutes of observation. It is concluded that delay in fixation of a magnitude, which is not uncommon in routine surgical pathology, may allow the majority of mitoses to terminate, resulting in unreliable assessments of mitotic activity.
mesh_terms: D000328:Adult; D000818:Animals; D003584:Cytological Techniques; D005260:Female; D005404:Fixatives; D006801:Humans; D008297:Male; D008677:Metaphase; D051379:Mice; D008819:Mice, Nude; D008938:Mitosis; D008940:Mitotic Index; D009368:Neoplasm Transplantation; D012516:Osteosarcoma / Q000473:pathology*; D011418:Prophase; D012513:Sarcoma, Experimental / Q000473:pathology; D013692:Telophase; D013997:Time Factors; D014021:Tissue Preservation; D014183:Transplantation, Heterologous
chemical_list: D005404:Fixatives