AminoGlo^TM

Improved Fluorescence Labeling of Amino Groups

AminoGlo^TM is now available for conjugation to free amino groups on proteins for immunoassays and for oligonucleotide labeling. Advantages are its high reactivity with amines, high quantum yield, and a large Stokes shift which allows it to be used with mercury arc line source at 365 or 401 nm, and the fluorescence collected through a broad band filter with a cut on > 425 nm.

This succinimidyl ester of a highly fluorescent benzocoumarin, reacts quickly in mixed solvent (acetonitrile/buffer solutions) to yield protein/dye conjugates which are easily separable from the unreacted dye by extraction of the precipitated conjugate with acetonitrile. The dye/protein ratio achievable with any given protein depends on the number of free amine groups and the pH of the solution it will be used in. High ratios can be prepared at a pH above 8, but the hydrophobicity of the dye causes precipitation of the high dye/protein conjugates. If redissolved at lower pH where most amine groups in the protein are protonated, moderately high dye/protein ratio conjugates can exist in solution. In the case of avidin, dye/avidin ratios up to 3:1 remain in solution at pH 7.0, whereas, ratios greater than 3:1 are soluble at a pH of 4.0. The photostability of AminoGlo^TM 1/avidin conjugates is a factor of 34 greater than that of fluorescein/avidin conjugates when irradiated at the excitation maximum and at the same photon flux.

For pricing and availability, please contact:

Dr. Victor Koch at 541.207.3844

email: koch@covalentassociates.com