Synthesis and characterization of FITC-aminated agarose as highly-fluorescent labeling agent

Organic fluorescence agent designed into nanoparticle can significantly promote its fluorescent efficiency. In this pape, a novel fluorescein isothiocyanate labeling aminated agarose (FITC-AA) is prepared and tested as an effective fluorescent labeling agent. IR analysis and EA proved that FITC was grafted to the aminated agarose (AA) successfully. FITC-AA spontaneously formed nanoparticle with a diameter between 159.2 nm and 1530 nm at below 37C by gelling effect of agarose. Cell culture experiments confirmed that HL-60 cells and 3T3 fibroblast cells could be fluorescently marked by FITC-AA nanoparticles and their fluorescence sustained longer than by FITC. After deposited for half a year, FITC-AA can reversibly dissolve in hot water and form nanoparticles when cooling to 37C, and its fluorescent properties remain. These findings demonstrate that FITC-AA is an effective labeling agent for marking cells.