[Testing pararosanilines and fuchsins histophotometrically for their usefulness in the quantitative PAS-reaction (author's transl].

Seven pararosanilines and nine fuchsins of different sources have been compared histophotometrically to "Pararosanilin acridinfrei" (Bayer). With respect to the quantitative evaluation of the PAS-reaction three problems are investigated: 1) Wavelength of extinction maxima of the reaction products; 2) Influence of the disulfite concentration; 3) Possibility to differentiate between long time and short time oxidized liver sections. The reaction products of the tested reagents are not comparable with the control substance. Partly there are many reaction products with different maxima. In all reaction products, except Pararosaniline Chloride (Gurr), the extinction maxima are shifting with variations in the disulfite concentration. The difference of the oxidation time is reproduced by five substances half as good as by the control substance, some substances reproduce the difference worse, and some substances do not differentiate in any way between different oxidation times. It is impossible to compare the results of PAS-reactions quantitatively using different colouring substances.