"20 ml DMSO and 80 μl pyridine were mixed with 1 g Car and stirred at 70 °C for 30 min. After adding 0.1 g FITC and 40 μl dibutyltin dilaurate, the mixture was incubated for 3 h at 70 °C. The Car was then precipitated and washed repeatedly with ethanol 95% until the waste solvent became colorless. The precipitate was dissolved and dialysed against Milli-Q water in order to remove any residual free FITC. The FITC absorbance at 480 nm of the bath water was checked and the dialysis process was considered complete when the absorbance was negligible. After purification the labelled Car was freezedried." from the article "Mobility of carrageenan chains in iota- and kappa carrageenan gels".