Group of substances for fixation purposes

摘要

Toxic formalin can be substantially, in some cases completely, replaced in various types of fixation procedures in histology/anatomy/microbiology by tannic acid and/or organic and inorganic substances having a similar action. It is also possible to use a 0.1-0.3% strength tannic acid solution even for the transport of histological material. Even weak solutions of tannic acid have astringent effects whereas, which is unfavourable for microscopic evaluation of histological specimens, the conventional aqueous formalin solutions (for example 1 part of formol in 9 parts of water) usually act to swell cell nuclei and body cells. Tumour assessment can, for example, be facilitated by the tannin fixation.