amaranth solution

am·a·ranth so·lu·tion

a 1% solution of amaranth (trisodium naphthol sulfonic acid), a synthetic vivid red dye, stable in acid and intensified in sodium hydroxide solution; used as a red or pink colorant in liquid pharmaceuticals.
References in periodicals archive ?
Different concentration of BSA and Nisin protein from 0 to 15 mg/mL were mixed with Amaranth solution (2mg/mL) in separate test tubes and incubated at 37 0C for two hours.