Some Features Of Fixation Of Organs And Tissues Of Laboratory Animals For Quality Of Gistological Analysis

K. Koptyaeva, researcher, pathomorphologist, A. Muzhikyan, PhD veterinary medicine, senior researcher, Head of the Laboratory of Histology and Pathomorphology, Ya.Gushchin, researcher, pathomorphologist, E. Belyaeva, researcher, pathomorphologist, M. Makarova, Director, V. Makarov, Doctor of Medicine, Professor, Deputy dir. of science JSC «Research-and-manufacturing company «Houm оf Pharmacy», 188663, Russia, Leningradskiy region, Vsevolozhskiy district, Kuzmolovskiy, st. Zavodskaya, 3. b. 245 Е-mail:


Fixation of organs and tissues precedes the direct preparation of histological preparations. The quality of fixation affects the achievement of microscopic research, so it is very important to choose the most optimal methods of fixation individually. In this study considering the most common methods of fixation that are used at the stage of preclinical research. Based on the results of the work, the recommendations were made on the use of the perfusion method of fixation, endotracheal instillation with fixative and fixation of the standard organocomplex of small laboratory animals. It was found that the perfusion method of fixation provides full and instantaneous fixation and lack the artificial changes related to autolytic processes in organs. Disadvantages of this method are the inability to determine the blood vessel filling after washing out the blood and examine the tissue for hemorrhagic changes. By tracheal instillation of the lungs the best quality of organ fixation and the absence of artifacts characteristic of postmortal fixation (i.e., focal atelectasis, desquamation of the bronchial epithelium) were noted. Nevertheless, this method can’t determine the presence of hemorrhages, emphysema and the localization of inflammatory exudate in the bronchi. Besides, in this work was defined the optimal volume of 10% neutral formalin for complete postmortal fixation of the standard organocomplex of mice, rats and rabbits.


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