FITC-Dextran (MW 4000) (solution) 

FITC-Dextran (MW 4000) (solution) 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].
Solution Concentration: 2 mM

Guidelines (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 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.
Storage: The stock solution, store at -20°C or -80°C away from light and avoid repeated freezing and thawing.
Note: Sterilize by filtration through a 0.22 μm filter.

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. Incubate cells at 43.5°C for 1 hour and at 37°C for 8 hours to induce apoptosis.
2.2. Suspend the cells in 100 μL of medium, and mix in Q-prep tubes with 10 μL of propidium iodide (PI), 10 μL of FITC-Dextran (MW 4000) (the final concentration of PI and FITC-Dextran (MW 4000) is 7.5 μM and 1.13 μM, respectively).
2. 3. Incubate cells for 25 min at room temperature in the dark.
2. 4. Take the labeled cells with 3 mL of medium and centrifuge for 10 min at 500 g.
2. 5. Take centrifuged cells with 1 mL of medium and use flow cytometry or fluorescence microscopy analyze (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.

60842-46-8

[FITC-Dextran (MW 4000) (solution)]

Room temperature in continental US; may vary elsewhere.

Please store the product under the recommended conditions in the Certificate of Analysis.

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

  [2]. 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]

  [3]. 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).

  [4]. 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]

  [5]. 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]