Cy3 Acid

Catalog#: 1300-5
Unit size: 5 mg
In stock
Catalog#: 1300-25
Unit size: 25 mg
In stock
Catalog#: 1300-100
Unit size: 100 mg
In stock

Cy3 Acid (also sold under Sulfo-Cyanine3 Acid) is a bright, water-soluble, and pH insensitive from pH 4 to pH 10 orange-fluorescent dye. Cy3 conjugates of antibodies, peptides, and proteins can be excited using the 532 nm or 555 nm laser line and visualized with TRITC (tetramethylrhodamine) filter sets. Cy3 conjugates give less background than TAMRA and most other commonly used fluorescent dyes.

The carboxylic acid of Cy3 dye is a reagent of choice for the preparation of custom activated esters that often are not commercially available. Examples of such activated esters include sulfo-NHS, TFP (2,3,5,6-Tetrafluorophenol), STP (4-Sulfo-2,3,5,6-Tetrafluorophenol, Sodium Salt). Another common application for non-activated carboxylic acid is peptide modification during solid phase synthesis, which usually requires in-situ activation with peptide coupling regents, for example HATU. Cy3 Acid is also often used for control experiments, and for calibration.

Abs/Em Maxima
555/572 nm
Extinction coefficient
150,000 cm-1M-1
Water, DMSO, DMF
Spectrally similar dyes
Cy3, DyLight® 555, Alexa Fluor® 555
Molecular weight
Storage conditions
Shipping conditions
Ambient temperature

Enter only one — either volume or amount of protein to be labeled
Enter only one — either maximum concentration of DMSO or volume DMSO added to label

Cy®Dye is a trademark of GE Healthcare.