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 visualisation of neuronal morphology. Hydrazides also can be used for labelling aldehyde or ketone groups, such as carbohydrate molecules after peroxidation with periodate. However, for this application it is recommended that CF® dye aminooxy forms are used, 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 labelling in cases where lysine modification alters the biological activity of the labelled 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 labelling efficiency.

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