Biotium offers a number of reactive dye formats for labelling proteins, nucleic acids, and other biomolecules with fluorescent dyes. CF® dyes offer advantages in brightness and photostability compared other similar commercial dyes. CF® dyes are available in a number of reactive dye formats for CF® dye colours span the visible and near-infrared spectra.

Amine groups react with activated carboxylic acids. Aminooxy (also known as hydroxylamine) groups readily react with aldehydes or ketones without the need for a reducing agent. Hydrazides can be microinjected into cells as fixable polar tracers for visualization of neuronal morphology. Hydrazides also can be used for labeling aldehyde or ketone groups, such as carbohydrate molecules after peroxidation with periodate. However, for this application we recommend using CF dye aminooxy forms, which are more reactive toward these groups than hydrazide forms. Maleimide reactive dyes label thiols, such as cysteine residues in proteins, and can be used as an alternative to SE labeling in cases where lysine modification alters the biological activity of the labeled protein. Succinimidyl ester (SE) groups label free amines, such as lysine residues in proteins, and are commonly used to label antibodies. CF® dye SE groups are more resistant to hydrolysis compared to most commercially available SE dyes, resulting in improved stability and labeling efficiency. SE Protein Labeling Kits include CF® dye SE and other components required to label and purify proteins. The kits are sufficient for three labeling reactions of 1 mg protein each.

CF® dye technologies are covered by pending US and international patents. CF® is a registred trademark of Biotium, Inc. AlexaFluor® is a registered trademark of Molecular Probes, Inc.

Biotium's line of CF® dyes offer advantages in brighness and/or photostability compared to Alexa Fluor® dyes and other similar commercial dyes. CF™ dyes are available in a number of reactive dye formats for CF™ dye colors span the visible and near-infrared spectra. See the CF® Dye Reference Table under the Datasheets tab to select the dye colors that are optimal for your application and instrument.