FITC-Chitosan (MW 100000)

FITC-Chitosan (high molecular weight, e.g., 300 kDa, 18 kDa) can be used to prepare fluorescence-labeled nanoparticles and investigate cellular uptake and in vivo biodistribution of nanoparticles^[1][3].

Guide (the following is a recommended protocol for reference only, which can be adjusted according to actual requirements).
1. Cell culture: Seed cells in multi-well plates or confocal culture dishes, and culture them in medium containing 10% FBS until reaching 70-90% confluency.
2. Experimental procedures:
2.1 Wash cells with PBS or serum-free medium. Add fresh serum-free medium containing FITC-Chitosan or its nanoparticles at different concentrations.
Key controls: Set up two temperature groups, 37°C (allowing internalization) and 4°C (inhibiting internalization, mainly investigating surface adsorption).
2.2 Incubation: Incubate cells in a cell incubator for 0.5 to 4 hours (determine the linear uptake phase according to pre-experiments).
2.3 Termination and washing: Immediately after incubation, wash cells 3-4 times with pre-cooled PBS to terminate the reaction and remove unbound nanoparticles.
2.4 Membrane surface fluorescence quenching (optional but recommended): To distinguish FITC-Chitosan bound to the cell surface from internalized FITC-Chitosan, digest cells with 0.25% trypsin at 37°C for 30 minutes to remove surface-bound probes, followed by another wash with PBS.
3. Cell lysis and fluorescence quantification:
3.1 Add 0.2 N NaOH solution containing 0.5% Triton X-100 to lyse cells.
3.2 Transfer the cell lysate to a black opaque 96-well plate.
Measure the fluorescence intensity using a fluorescence microplate reader at Ex/Em = ~485/535 nm.
3.3 Convert the fluorescence value to the mass of FITC-Chitosan taken up by cells via a FITC-Chitosan standard curve (prepared in the same lysate).

MedChemExpress (MCE) has not independently confirmed the accuracy of these methods. They are for reference only.