FITC-Dextran (MW 4000) 

FITC-Dextran (MW 4000) is a fluorescent probe for fluorescein isothiocyanate (FITC) dextran (Ex=495 nm; Em=525 nm). FITC-Dextran (MW 4000) can be used as a marker to reveal heat shock-induced cell damage and to study the early and late stages of apoptosis. FITC-Dextran (MW 4000) can also be used for cell permeability studies, such as blood-brain barrier permeability and determination of the extent of blood-brain barrier disruption^[1][2][3].

Guide (Following is our recommended protocol. This protocol only provides a guideline, and should be modified according to your specific needs).
1. Solution preparation
^[2] 1.1 Preparation of storage solution
Solvent: Ultrapure water
Concentration: 10 mg/mL is recommended (e.g. weigh 10 mg FITC-Dextran (MW 4000) and dissolve in 1 mL solvent).
Note: Sterilize by filtration through a 0.22 μm filter.
1.2 Preparation of working solution
Dilute to 0.1 mg/mL with PBS or serum-free cell culture medium (optimized according to the experiment).
Note: The working solution should be prepared and used immediately, and protected from light.
2. Cell staining
Labeling of cells^[1]:
For use with apoptotic HeLa cells and human peripheral blood mononuclear cells (PBMC) (viable HeLa and PBMC can not be stained by FITC-Dextran).
2.1 After cell apoptosis induction, suspend cells in 100 μL of culture medium, and mix with propidium iodide (PI) and FITC-Dextran (MW 4000) in a Q-prep tube. The final concentrations of PI and FITC-Dextran (MW 4000) are 7.5 μM and 1.13 μM, respectively.
2.2 Incubate the cells for 25 minutes at room temperature in the dark.
2.3 Collect 3 mL of labeled cell suspension and centrifuge at 500 g for 10 minutes.
2.4 Resuspend the pelleted cells in 1 mL of culture medium, and analyze by flow cytometry or fluorescence microscopy (PI: Ex = 500 nm, Em = 600 nm; FITC-Dextran (MW 4000): Ex = 495 nm, Em = 525 nm).

Paracellular permeability measurement^[4]
1. Add FITC-dextran (0.1 mg/mL) to the basal media in the transwell chamber.
2. Collect media from the transwell insert after 15 min.
3. Measure the fluorescence signal (Ex = 485 nm, Em = 538 nm).
4. Calculate FITC-dextran concentration based on fluorescence intensity.
5. Calculate permeability.

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

Guidelines (Following is our recommended protocol. This protocol only provides a guideline, and should be modified according to your specific needs).
For intestinal barrier function assay^[5]
1. Fast mice for 4 h.
2. Orally gavage mice with FITC-Dextran MW 4000 (0.6 mg/g).
3. Measure fluorescence intensity of plasma in 4 h (excitation nm/emission 520 nm).

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

4000.00(Average)

60842-46-8

Solid

Yellow to orange

525

488

[FITC-Dextran (MW 4000)]

Room temperature in continental US; may vary elsewhere.

4°C, protect from light

*In solvent : -80°C, 6 months; -20°C, 1 month (protect from light)

• [1]. Moumaris M, et al. Fluorescein isothiocyanate-dextran can track apoptosis and necrosis induced by heat shock of peripheral blood mononuclear cells and HeLa cells[J]. Open Biological Sciences Journal, 2015, 1(1).

  [2]. Natarajan R, et al. Fluorescein Isothiocyanate (FITC)-Dextran Extravasation as a Measure of Blood-Brain Barrier Permeability. Curr Protoc Neurosci. 2017 Apr 10;79:9.58.1-9.58.15.  [Content Brief]

  [3]. Eriksson I, et al. Analysis of Lysosomal pH by Flow Cytometry Using FITC-Dextran Loaded Cells. Methods Mol Biol. 2017;1594:179-189.  [Content Brief]

  [4]. Okabayashi K, et al. Cdc42 activates paracellular transport in polarised submandibular gland cells. Arch Oral Biol. 2021 Dec;132:105276.  [Content Brief]

  [5]. Yu W, et al. ACE2 contributes to the maintenance of mouse epithelial barrier function. Biochem Biophys Res Commun. 2020 Dec 17;533(4):1276-1282.  [Content Brief]