How does formalin preserve biological specimens?

Created from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.

structural formulas of some organic compounds — organic compound The structures of organic compounds can be depicted in condensed, expanded, and three-dimensional structural formulas.

Formalin is an aqueous solution of formaldehyde, which is an organic compound and the simplest of the aldehydes.12

Formalin preserves biological specimens primarily through its high reactivity with proteins. By reacting with these proteins, formaldehyde effectively cross-links them, which stabilizes the tissue structure and prevents decay. This same chemical property is the basis for its use as an embalming agent, a disinfectant, and in the tanning industry.2

It is important to note that formaldehyde is a hazardous substance; it is a colourless, flammable gas that is highly irritating to mucous membranes and is classified as a human carcinogen.2