Table 2.

Fixation Procedures Previous to Embedding in PEG.

Fixative	Composition	Objective	References
Karnovsky’s solution	2.5% glutaraldehyde and 4.5% formaldehyde in phosphate buffer (0.1 M, pH 7.2)	Histological fixation	Karnovsky42
Ferrous sulfate/formalin	4 ml of 37% formaldehyde, 10 g of Iron(II) sulfate heptahydrate, and fill up to 100 ml with distilled water	Fixation with precipitation of soluble phenolics (black precipitates)	Johansen3
Caffeine/sodium benzoate	0.5 g pure caffeine, 0.5 g sodium benzoate, 10 ml distilled water, 90 ml butyl alcohol	Fixation of the polyphenols/flavanols	Feucht et al.34

Abbreviation: PEG, Polyethylene glycol.