Karnovsky fixative
Mixtures containing formaldehyde and glutaraldehyde , this mixture is often designated Karnovsky fixative
The combination of formaldehyde with glutaraldehyde as a fixative for electron microscopy takes advantage of the rapid penetration of small HCHO molecules, which trigger the structural stabilization of the tissue. The rapid and complete crosslinking is caused by the slower penetrating glutaraldehyde oligomers. This mixture is associated with the name of Morris J. Karnovsky of Boston. This is an example of a great innovation that was only published in an unrevised summary (Karnovsky, 1965). Its original mixture contained 4% glutaraldehyde, which was a higher concentration than many people wanted to use (Hayat, 1981). Designations like
“Karnovsky at half strength” became common language in the 1960s and 1970s. Fixers of this type allowed for definitive descriptions of EM level histology that were accomplished in the next 5 or 6 years the introduction of Karnovsky’s fixer, and they are still commonly used.
The references
Baker, JR (1958). Principles of biological microtechnology (reprinted in 1970, with corrections). London: Methuen.
Carson, FL, Martin, JH & Lynn, JA (1973). Fixing formalin for