Trypan blue, carcinogen

A Trypan blue is a suspected carcinogen. Gloves should be worn when using all stains. 

Oil orange SS [2646-17-5], and Trypan blue [72-57-1]. Also, lARC has listed some dyes as nonclassifiable as to carcinogenicity to human in their Group 3 category. The studies on their carcinogenic effects were inconclusive. 

The stain may fade with time but can be restored by immersion in a dilute NaOH solution. Methanol lost by evaporation of the stock solution can be replenished. Trypan Blue is a suspected carcinogen and all suitable precautions should be taken. In the writer s laboratory all paper towels and liquids containing the stain are collected in a pail and incinerated. It is available from Aldrich Chemicals, 1001 West Saint Paul Ave., Milwaukee, Wisconsin, 53233. Tel (414) 273-3850, Fax (414) 273-4979. 

A characteristic example is the case of some bisazodyes. Lloyd et al. have shown that trypan blue is a powerful inhibitor of add hydrolases and that when injected in the rat the dye concentrates in the lysosomes of phagocytic tissues. They reason, therefore, that the dye could conceivably inhibit acid hydrolases in vivo. According to these authors, there is a relationship between this phenomenon and the teratogenic and carcinogenic effects of the dye. 

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