Strong formalin 150 mL
Picric acid, sat in ethanol   185 mL
Ethanol, 100% 235 mL
Water 430 mL
Trichloroacetic acid 5 g

Dissolve the trichloroacetic acid in the water, then combine with the other ingredients.

Davenport says this solution gives results very similar to Bouin's fluid, but with less tendency to swell connective tissue. In addition, the ethanol content facilitates penetration of fatty tissues, including brain and spinal cord. PFT stands for picric-formalin-trichloroacetic.

The method he gives specifies 850 mL of a 2% picric acid solution in 50% ethanol, plus the formalin and trichloroacetic acid. The amounts of saturated alcoholic picric acid, ethanol and water given above provide that, based on picric acid saturating in ethanol at 9%.

Average sized pieces of tissue should be fixed following overnight treatment. No particular aftertreatment was given.


Davenport, H.A., (1960),
Histological and histochemical techniques,
W. B. Saunders Co., London, UK., Oxford, UK.




Translate in
Google Translate