Darrow Red, A New Basic Dye

A new red basic dye, which has specificities similar to blue basic dyes and which exhibits metachromasia, has been named Darrow red, and is now commercially available. In a staining solution, prepared as indicated, it is stable for about 1 mo. Procedure: Dissolve 50 mg of Darrow red in 200 ml of 0.2 M acetic acid. Boil gently for 10 min; cool and filter. Stain frozen sections or decerated and hydrated mounted paraffin sections 20-30 min. Differentiate and dehydrate rapidly in 50, 70 and 95% ethyl alcohols followed by n-butyl alcohol, xylene and covering in synthetic resin.