Question.
Could you please share your best recipe for the Modified Davidson's Fixative?
Answer 1.
There are several formulations (some are probably typos), but this seems to be one commonly cited.
Modified Davidson's Fixative: (Latendresse, J. R., Warbrittion, A. R., Jonassen, H., & Creasy, D. M. (2002). Fixation of testes and eyes using a modified Davidson's fluid: comparison with Bouin's fluid and conventional Davidson's fluid. Toxicologic pathology, 30(4), 524-533.)
- 37–40% formaldehyde --- 30ml
- Absolute ethanol ----------15ml
- Glacial acetic acid --------- 5ml
- Distilled Water ------------ 50ml
Tony Henwood MSc, BAppSc, GradDipSysAnalys, CT(ASC), FFSc(RCPA) (Retired), University of Western Sydney
Answer 2.
The "Davidson's" name is, as Tony says, applied to various mixtures. In these, formalin is acidified with acetic acid in solutions that also contain some alcohol (typically about 33% v/v) but probably not enough to contribute to fixation.
The mixture quoted from Latendresse et al. 2002 has only 15% alcohol - about the same as in a good dry sherry. (My gastric mucosa is not yet fixed.) The Histonet archives must surely still contain Dr Bob Richmond's contributions about "Davidson's fixative" in the 1990s or 2000s.
John Kiernan, London, Canada