In vitro toxicity assays for dye ligands used in affinity chromatography

Some reactive textile dyes have been used for years as biomimetic ligands in protein purification. There has been reluctance, however, to use these dyes on a large scale for therapeutically applicable proteins for fear of possible dye leakage and consequent contamination. Therefore, toxicological data are necessary to quantify the level of this hazard. This study deals with a series of in vitro toxicity investigations with eukaryotic cells (growth, polyploidy, etc.) and with prokaryotic cells (Escherichia coli) for genotoxic studies. Both approaches demonstrated a lack of or slight toxicity for Reactive Blue 2 and Reactive Red 120 and their derivatives over the range 10-62.5 micrograms/ml in several assays.