Wikipedia
Epicocconone
Epicocconone is long Stokes' shift fluorescent dye found in the fungus Epicoccum nigrum. Though weakly fluorescent in water (green emission, 520 nm) it reacts reversibly with proteins to yield a product with a strong orange-red emission (610 nm). This dye can be used as a sensitive total protein stain for 1D and 2D electrophoresis, quantitative determination of protein concentration, making it a powerful loading control for Western blots.