Use of terpene-based solvents (Hemo-De, Histoclear, and Shandon and BDH xylene substitutes) in place of xylene in the Ehrlich indole test

Although less effective than xylene and Kovacs reagent as indole extractants, Hemo-De and Shandon xylene substitute can be used in the Ehrlich indole test if a less toxic solvent is desirable. In doubtful cases, xylene should be used. Because of the blocking action shown in the test, use of indole-nitrite broth cannot be recommended.