Chromeo™ P540 detects proteins and peptides by exhibiting a color change from purple to red. After binding to primary amines, it undergos a large shortwave spectral shift of 54nm that is visible to the naked eye. There is also a large increase in quantum yield that changes the non- or only weakly fluorescent dye into a bright fluorescent conjugate. The shift of the JPorption & emission bands together with the increased fluorescence quantum yield effectively eliminates background from any unbound dye. In addition, because unbound the pyrylium dye is hydrolyzed during the labeling procedure, there is no need for purification following the simple one-step, room-temperature incubation. The labeled protein is ready to use immediately, and any possible background from the unbound dye is eliminated. Due to the unique conjugation mechanism, proteins labeled with Py-Dyes maintain their native charge and isoelectric point. Because of their unique features, Chromeo Py-Dyes have been used successfully in a number of “no-wash” applications such capillary electrophoresis, SDS-protein gel electrophoresis, isoelectric focusing or as a label in receptor binding studies.

An amine-reactive pyrylium dye

Store at 4° C

Solid

λex 587 nm in water; λex 533 nm, λem 627 nm in water (conjugated)