 Some dyes sold as alcian blue 8G are unstable in solutions at pH 5.6 and above; they precipitate in less than 24 hours.Batches of alcian blue that do not form stable solutions cannot be used in Scott's "critical electrolyte concentration" methods for histochemical characterization of different glycosaminoglycans, which require solutions at pH 5.7-5.8 with variable concentrations of MgCl2.The pyridine variant of alcian blue (Alcian Blue-tetrakis(methylpyridinium) chloride, CAS 123439-83-8, CB6503730, PubChem 24860335) is more stable than the original alcian blue dyes and may be just as good as a stain..

Nucleic acids are generally basophilic because they have a very high density of negative charge due to the sugar phosphate backbone.