MB™ 543 is a very hydrophilic, water-soluble orange fluorescent dye. Structurally related to Alexa Fluor® 546 dye, MB™ 543 dye contains an additional, negatively charged sulfo group (SO3H) to improve water solubility and minimize self-quenching. Characteristic features of MB™ 543 are strong absorption, high fluorescence quantum yield, high photostability, and pH insensitivity from pH 3 to pH 10. MB™ 543 is a highly suitable dye for single-molecule detection applications and high-resolution microscopy such as PALM, dSTORM, STED etc.
MB 543 Azide reacts with terminal alkynes via a copper-catalyzed click reaction (CuAAC). It also reacts with strained cyclooctyne via a copper-free click chemistry reaction to form a stable triazole and does not require Cu-catalyst or elevated temperatures.
For the detection of low abundance targets or where significant increase in signal intensity is desired please consider using next generation azides probes containing an internal copper-chelating motif.