Bouin solution, or Bouin's solution, is a compound fixative used in histology.[1] It was invented by French biologist Pol Bouin and is composed of picric acid, acetic acid and formaldehyde in an aqueous solution.[2] Bouin's fluid is especially useful for fixation of gastrointestinal tract biopsies because this fixative allows crisper and better nuclear staining than 10% neutral-buffered formalin. It is not a good fixative when tissue ultrastructure must be preserved for electron microscopy. However, it is a good fixative when tissue structure with a soft and delicate texture must be preserved. The acetic acid in this fixative lyses red blood cells and dissolves small iron and calcium deposits in tissue. A variant in which the acetic acid is replaced with formic acid can be used for both fixation of tissue and decalcification.[3] The effects of the three chemicals in Bouin solution balance each other. Formalin causes cytoplasm to become basophilic but this effect is balanced by the effect of the picric acid. This results in excellent nuclear and cytoplasmic H&E staining. The tissue hardening effect of formalin is balanced by the soft tissue fixation of picric and acetic acids. The tissue swelling effect of acetic acid is balanced by the tissue shrinking effect of picric acid.[4]
Hydrated sections of formaldehyde-fixed tissue are usually pre-treated with Bouin solution to obtain correct results in the trichrome stains for contrasting colours in collagenous and cytoplasmic (muscle) fibres. The trichrome methods were devised for tissues fixed in acidic mixtures containing mercuric chloride, which are now used only on a small scale.) Only the picric acid component of Bouin's solution is needed to bring about this correction of trichrome staining.[5]
When using Bouin solution, several potential problems can arise. Due to the formalin in the solution, formalin pigment may be present when viewing tissue sections under the microscope. Wet tissue should be fixed in Bouin solution for less than 24 hours. Excess picric acid should be washed out of tissue using several alcohol and water solutions or staining quality may deteriorate over time. Wet tissue fixed in Bouin solution should be stored in an alcohol and water solution rather than Bouin solution. Since Bouin solution contains formaldehyde, picric acid and acetic acid, appropriate safety precautions for these substances should be taken and regulations followed. In particular, noting that picric acid can be explosive, sensitive to friction and shock when dry and in contact with some metals can form unstable metal picrates.
Under the name "Bouin's fluid" this fixative is also widely used for marine invertebrates.[6] It is prepared as follows: picric acid, saturated aqueous solution – 75 ml; formalin, 40% aqueous solution – 25 ml; acetic acid, glacial – 5 ml.[7]
^Carson, Freida L.; Hladik, Christa (2009). Histotechnology: A Self-Instructional Text (3 ed.). Hong Kong: American Society for Clinical Pathology Press. p. 19. ISBN 978-0-89189-581-7.
^Culling, C.F.A. 1974. Handbook of Histopathological and Histochemical Techniques (including museum techniques), 3rd ed. London: Butterworths, p.49.
^Bancroft, John D.; Gamble, Marilyn, eds. (2008). Theory and Practice of Histology Techniques (6 ed.). China: Churchill Livingstone Elsevier. p. 72. ISBN 978-0-443-10279-0.
^Baker, J.R. 1958. Principles of Biological Microtechnique. London, Methuen, pp.149-150.
^Kiernan, J.A. 2015 Histological and Histochemical Methods. Theory and Practice. Banbury, UK: Scion, p.195.
^Lincoln, Roger J.; Sheals, John Gordon, eds. (1979). Invertebrate Animals - Collection and Preservation (1 ed.). UK: British Museum (Natural History). p. 128. ISBN 0-521-296773.
^Culling, C.F.A. 1974. Handbook of Histopathological and Histochemical Techniques (including museum techniques), 3rd ed. London: Butterworths, p.49.
Bouinsolution, or Bouin'ssolution, is a compound fixative used in histology. It was invented by French biologist Pol Bouin and is composed of picric...
Bouin may refer to: Bouin, Deux-Sèvres, in the Deux-Sèvres department Bouin, Vendée, in the Vendée department Isle of Bouin, a former island in the Vendée...
André Bouin (11 June 1870 – 5 February 1962) was a French histologist and reproductive endocrinologist. He is best known for the fixative Bouinsolution named...
to etch magnesium alloys, such as AZ31. Bouinsolution is a common picric-acid–containing fixative solution used for histology specimens. It improves...
symptoms for testicular cancer. After removal, the testicle is fixed with Bouin'ssolution because it better conserves some morphological details such as nuclear...
1723G. doi:10.1002/rcm.776. hdl:2268/322. PMID 12207359. Daubenfeld T, Bouin AP, van der Rest G (September 2006). "A deconvolution method for the separation...
ensembles) were built between the 1960s and 1970s to provide a low-cost solution for a rapidly expanding population: These districts were socially mixed...
Williams 1984, pp. 35–36. Ortiz-Hidalgo, Carlos (1992). "Pol André Bouin, MD (1870-1962). Bouin's fixative and other contributions to medicine". Archives of Pathology...
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grenades into a group of Luftwaffe men watching a football game at the Jean-Bouin Stadium in Paris, killing eight and wounding 13. The Germans claimed three...
needed (daily during major tournaments). The surface was a state-of-the art solution, in 1928, to the biggest problem with natural clay courts: poor drainage...
measured. He dismissed the unfortunate Varé and Hittorff, and designed the solution himself; an upper lake and a lower lake, divided by an elevated road, which...
Echos. Retrieved 28 September 2023. "Réutiliser les eaux usées, une bonne solution pour économiser l'eau ?". Ouest France. Retrieved 15 September 2023. "Disneyland...
was then the current practice – in a campus in the suburbs. The latter solution was also chosen by the twin university of Orleans. Royer's long term as...
employees. Public bodies also contribute. Given the interest in the technical solution provided by the funicular for public passenger transport over relatively...