Fluorescein di(β-D-galactopyranoside)  (Synonyms: FDG)

Fluorescein di(β-D-galactopyranoside) is a fluorogenic substrate for β-galactosidase (λ_ex=485 nm, λ_em=535 nm).

Guidelines (the following is our recommended protocol; this protocol is provided for guidance only and should be modified according to your specific needs).
Assay of senescence-associated β-galactosidase (SA-βG) activity^[1].
The cells (5×10³ cells per well) are cultured in a 96- well plate.
Wash with PBS.
Fixed for 5 min in 2% formaldehyde and 0.2% glutaraldehyde buffered with PBS.
Washing thrice in PBS.
An aliquot (100 μL) of the reaction buffer (i.e., the staining solution without X-Gal) is added into each well (containing 3.7 mL 0.2 M citric acid, 6.3 mL 0.4 M Na2HPO4 (citrate-phosphate buffer), 1 mL 100 mM potassium ferricyanide, 1 mL 100 mM potassium ferrocyanide, 0.6 mL 5 M NaCl, 0.2 mL 0.2 M MgCl2, and 7.2 mL deinozied water in a total volume of 20 mL is used) .
10 μL of 2 mM FDG is added per well and the plate was incubated in the dark at 37°C for 24 h without CO₂ supply.
The fluorescein fluorescence was measured using a fluorometer (Ex/Em = 485/535 nm).

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

656.59

C₃₂H₃₂O₁₅

17817-20-8

Solid

Yellow to orange

520

488

O=C1OC2(C(C=CC(O[C@@H]([C@@H]([C@@H](O)[C@H]3O)O)O[C@@H]3CO)=C4)=C4OC5=CC(O[C@@H]([C@@H]([C@@H](O)[C@H]6O)O)O[C@@H]6CO)=CC=C25)C7=C1C=CC=C7

Room temperature in continental US; may vary elsewhere.

-20°C, protect from light

*The compound is unstable in solutions, freshly prepared is recommended.

* Please refer to the solubility information to select the appropriate solvent. The compound is unstable in solutions, freshly prepared is recommended.

• [1]. Yang NC, et al. A fluorimetric method using fluorescein di-beta-D-galactopyranoside for quantifying the senescence-associated beta-galactosidase activity in human foreskin fibroblast Hs68 cells. Anal Biochem. 2004 Feb 15;325(2):337-43.  [Content Brief]