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

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.