ATTO 490LS maleimide

Product Introduction

ATTO 490LS is a new fluorescent label featuring an extraordinary large Stokes-Shift of 165 nm. Thus the emission spectrum is almost completely separated from its absorption spectrum, making the dye highly suitable for multiplexing experiments, in particular in combination with ATTO 488 and ATTO 514. ATTO 490LS is very hydrophillic and shows excellent water solubility. The dye exhibits a relatively high fluorescence quantum yield, which is only slightly reduced after conjugation to biomolecules, e.g. proteins, even at high degrees of labeling (DOL). ATTO 490LS is an anionic dye. After conjugation to a substrate the dye carries a net electrical charge of -1.Maleimides are well suited for coupling to thiol groups. This is similar to iodacetamides, but maleimides do react more thiol selective. They do not show significant reaction with histidine or methionine. Hydrolysis of maleimides to a mixture of isomeric nonreactive maleamic acids can compete significantly with thiol modification, particularly above pH 8. Maleimides may be used for labelling of amines, which usually requires a higher pH than reaction of maleimides with thiols. find more information here