Bromocresol Green sodium salt is used as a pH indicator. It is a pH sensitive triphenylmethane dye useful in various colorimetric detection studies and as an activity tracking dye for DNA agarose gel electrophoresis. It is also used in TLC (thin-layer chromatography) for visualizing compounds containing functional groups having pKa less than 5.
Ghaedi, M.; Khajesharifi, H.; Yadkuri, A. M.; Roosta, M.; Sahraei, R.; Daneshfar, A. Cadmium hydroxide nanowire loaded on activated carbon as efficient adsorbent for removal of Bromocresol Green. Spectrochim. Acta, Part A 2012, 86, 62-68.
Chen, H.; Liao, Y. Photochromism based on reversible proton transfer. J. Photochem. Photobiol. A 2015, 300, 22-26.