What are the general properties of FITC-dextran?

FITC-dextran has an excitation maximum of 493 nm and an emission maximum of 518 nm. Optimal intensity is observed at a pH greater than 8. These conjugates are stable for more than 6 years when they are stored dry at an appropriate temperature (-20°C). FITC-dextran is highly soluble in water, making it ideal for a wide range of experiments. These conjugates have 0.001-0.020 mol FITC per glucose unit. Regarding the molecular properties of FITC-dextran, the fluorescein moiety is joined together by a thiocarbamoyl linkage and the labeling methods do not cause a depolymerization of the dextran. These low levels of substitution cause minimal charges to dextran, which is essential for permeability studies. FITC-dextrans are highly sensitive to the pH of the environment and can be used as pH-indicators as well.