Folate-FITC

Folate-FITC (EC-17) is a folate receptor alpha (FRα) targeting contrast agent with fluorescent properties in the visible light spectrum. The Folate-FITC maximum excitation and emission wavelengths are 490 nm and 520 nm, respectively^[1][2]. In Vitro:Guide (The following is our recommended protocol. This protocol is only a guide and should be modified according to your specific needs).
1.1 Preparation of storage solution ^[2]
Prepare 10 μM Folate-FITC stock solution.
Note: EC-17 storage solution is recommended to be stored at -20℃ or -80℃ in the dark after aliquoting.
1.2 Preparation of working solution
Dilute the storage solution with cell suspension or blood sample to make the final Folate-FITC concentration of 200 nM.
Note: Please adjust the concentration of Folate-FITC working solution according to the actual situation and prepare it before use.
2 Staining
2.1 In vitro cell staining
1) FR⁺ L1210A or KB cells were suspended at a concentration of 10⁶ cells/mL in PBS containing 2% fetal bovine serum (FBS).
2) 1 mL of cell suspension is added with 20 μL of 10 μM Folate-FITC stock solution to a final concentration of 200 nM.
3) The mixture is incubated at 37°C for 60 min.
4) The cells are washed twice with PBS and then resuspended at a concentration of 10⁶ cells/mL for subsequent analysis.
2.2 Whole blood sample staining
1) Blood is drawn from female nude mice and stabilized with 1000 units/mL Heparin (HY-17567) at a 1:1 dilution.
2) 10⁴ circulating tumor cells (CTCs) are added to a 500 μL blood aliquot and the sample is mixed by gentle vortexing for 30 s.
3) 10 μL of 10 μM Folate-FITC stock solution is added to 0.5 mL blood sample for a final concentration of 200 nM.
4) The blood-cell suspension is incubated at 37°C for 60 min.
5) To test labeling specificity, cells are pre-incubated with 10 μM free Folic acid (HY-16637) before adding EC-17.
6) Using a flow cytometer, analyze the labeled cells using the cyan (488 nm laser, 530 nm emission filter) and red (637 nm laser, 647 nm emission filter) channels.