Hematoxylin substitutes: a survey of mordant dyes tested and consideration of the relation of their structure to performance as nuclear stains.

In the search for hematoxylin substitutes 26 dyes were more or less extensively tested for performance as nuclear stains, usually in combination with aluminum, chronic, ferrous and ferric salts. Reports from the literature on hematoxylin substitutes were also considered, and efforts were made to obtain samples of favorably reported dyes and test them. The reports on anthocyanins include isolated reports on several berry juices and a considerable number of studies on Sambucus niger and Vaccinium myrtillus. None of these have so far been tested by us. Otherwise favorable reports have appeared on eleven synthetic dyes and on carmine, brazilin, and hematin. Except for one of the synthetics, naphthazarin, which is no longer fractured, we had samples of all of these. In addition, more or less unsuccessful trials were made on twelve dyestuffs, some of which were new syntheses designed to combine chelating capacity with nucleophilia. Following Fyg's report of blue nuclear staining with chrome alum carmine, trial was made to change the red nuclear stain of kernechtrot by altering the metal mordant. The most successful dyes were phenocyanin TC, gallein, fluorone black, alizarin cyanin BB and alizarin blue S. Celestin blue B with an iron mordant is quite successful if properly handled to prevent gelling of solutions.