The stock solution is the alcoholic solution of crushed berry of Berchemia lineata DC. a member of the genus Berchemia (Rhamnaceae). Sections are mordanted with ferric alum for at least 4 h., washed and stained with diluted solution of Berchemine. The sections are stained blue. If over-stained, decolorize with very dilute solution of ferric alum. Berchemine seems to be a basic dye, rather Karyophilic, not diffuse and not metachromatic.