AAT Bioquest

What are the factors that can affect dextran-FITC conjugation?

Posted May 10, 2023


There are several factors that can affect dextran-FITC conjugation. One factor is pH; the pH of the reaction buffer can affect the degree of conjugation as well as its stability. A pH of 8.0-9.0 is optimally used for conjugation reactions. Temperature can affect the rate of reaction. A reaction temperature of 4-25 degrees celsius is typically used for conjugation reactions. Reaction time can affect the quality of the conjugate. A reaction time of 1-2 is optimal for dextran-FITC conjugation. The FITC-to-dextran ratio is another factor, as high concentrations of either component may cause aggregation or incomplete conjugation. Low concentrations may cause low yield or a weak fluorescence signal. Lastly, other compounds such as proteins may interfere with the reaction due to the fact that they can compete with dextran for FITC attachment sites.

Additional resources

Fluorescein isothiocyanate (FITC)-Dextran Extravasation as a Measure of Blood-Brain Barrier Permeability

FITC–dextran conjugate (average MW = ~70K)

Cal-520®-Dextran Conjugate *MW 10,000*