Phloxine B Staining Solution is used in relative aciddophilia stain. The least acidophilic elements stained in the phloxine, control slide lose the red color after 2 minutes in the tartrazine solution. The most acidophilic retain the phloxine after 20 minutes in the tartrazine.
References: Lendrum, A.C, J. Path. Bact., 59:399-404, 1947 and Clark, G., (ed.), Staining Procedures, 3rd Edition, Williams & Wilkins, Baltimore, p. 163, c. 1973. In Cellosolve.