IR 650 NHS Ester (IRDye® 650 NHS Ester analog) is a water-soluble, bright, far-red-fluorescent dye and is spectrally similar to other 650 dyes that are used for flow cytometry, microscopy and other applications. IR 650 conjugates ideally suited for the 633 nm or 647 nm laser lines. A significant advantage to using long wavelength dyes such as Cy5® Dye or Alexa Fluor® 647 dye over other fluorophores is the low autofluorescence of biological specimens in this region of the spectrum.
The NHS ester (or succinimidyl ester) is the most popular amine reactive group for labeling with the primary amines of proteins (Lys), amine-modified oligonucleotides, and other amine-containing molecules. Proteins can be labeled with IR 650 NHS Ester at high molar ratios without significant self-quenching, leading to brighter conjugates and more sensitive detection. IR 650 conjugates can be used for detection of low abundance targets.