8] Acidic structures would be stained by basic dyes, while basic structures would be stained by acidic dyes
Eriochrome Black T (EBT) and Astrazon FGGL blue are acidic dyes.
A similar behavior was observed earlier for the biosorption of acidic dyes by Paenibacillus macerans  and direct azo dyes by Spirogyra sp.
90] investigated the removal of health hazard causing acidic dyes (acid violet 17, acid violet 49, acid violet 54, acid blue 15 and acid red 119) from aqueous solution by adsorption.
Removal of health hazard causing acidic dyes from aqueous solutions by the process of adsorption.
Summary: TEHRAN (FNA)- Researchers at Iran University of Science and Technology succeeded in improving the ability of nanosilica to adsorb acidic dyes
by functionalizing porous nanosilica.
Algerian researchers have discovered that orange peel could be used to remove acidic dyes
from industrial effluent.
Ion-pairing with acidic dyes
under the described conditions is less likely because the carboxy metabolite is a zwitterion.
Diarylguanidines are used in the dye industry to form salts with acidic dyes
or pigments that otherwise would be insoluble.
Anionic dyes are commonly known as acidic dyes
and widely employed in textile dyeing.
Anionic, acidic dyes
were separated using a buffer composed of 25 mM CHES [2-(N-cyclohexylamino)ethanesulfonic acid] (Sigma-Aldrich) and 5 mM [beta]-cyclodextrin (Sigma-Aldrich) and adjusted to a pH of 8.
Whereas in basic pH conditions, the interaction between acidic dyes
and Abelmoschus esculentus stem are destabilized resulting in decrease %age adsorption [20, 21].