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5,5'-dibromo-4,4'-dichloro-indigo is the product of X-gal cleavage, often used as a reporter with B-galactosidase. I've made the (unreferenced) observation that it seems as though the blue product slowly degrades over periods of time within the cell, allowing for cells to lose their blue coloration.

What mechanisms can explain the degradation of 5,5'-dibromo-4,4'-dichloro-indigo within cells?

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Can be 3 reasons: 1. Dilution 2. Reductive conversion to colorless leuco-indigo 3. Metabolic decay: I suspect the metabolism would be similar to that of purines – WYSIWYG May 7 '13 at 17:56
^ that was purely speculation – WYSIWYG May 7 '13 at 18:07
Indigo compounds are so damn insoluble I don't know if you can get it into an enzyme easily. I've made indigo ( not the x-gal indigo in the question, but same core structure ) just for fun while my boss isn't watching, and I haven't found any solvent that will dissolve it. But maybe glutathione can slowly reduce it. When I reduce the indigo I make, I use sodium dithionate and boiling water. GSH wouldn't be as powerful, but you don't need it to work as quickly. More pure speculation. – user137 Aug 1 '14 at 6:18

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