Fluorescein di(β-D-galactopyranoside) is the fluorescent substrate of β-galactosidase (λex=485 nm, λem=535 nm).

Physicochemical Properties

Molecular Formula	C32H32O15
Molecular Weight	656.58748
Exact Mass	656.174
CAS #	17817-20-8
PubChem CID	122063
Appearance	Yellow to orange solid powder
Density	1.74 g/cm3
Boiling Point	974.8ºC at 760 mmHg
Melting Point	200-203ºC (dec.)
Flash Point	316.5ºC
Vapour Pressure	0mmHg at 25°C
Index of Refraction	1.764
LogP	-0.2
Hydrogen Bond Donor Count	8
Hydrogen Bond Acceptor Count	15
Rotatable Bond Count	6
Heavy Atom Count	47
Complexity	1050
Defined Atom Stereocenter Count	10
SMILES	C1=CC=C2C(=C1)C(=O)OC23C4=C(C=C(C=C4)O[C@H]5[C@@H]([C@H]([C@H]([C@H](O5)CO)O)O)O)OC6=C3C=CC(=C6)O[C@H]7[C@@H]([C@H]([C@H]([C@H](O7)CO)O)O)O
InChi Key	ZTOBILYWTYHOJB-WBCGDKOGSA-N
InChi Code	InChI=1S/C32H32O15/c33-11-21-23(35)25(37)27(39)30(45-21)42-13-5-7-17-19(9-13)44-20-10-14(43-31-28(40)26(38)24(36)22(12-34)46-31)6-8-18(20)32(17)16-4-2-1-3-15(16)29(41)47-32/h1-10,21-28,30-31,33-40H,11-12H2/t21-,22-,23+,24+,25+,26+,27-,28-,30-,31-/m1/s1
Chemical Name	3',6'-bis[[(2S,3R,4S,5R,6R)-3,4,5-trihydroxy-6-(hydroxymethyl)oxan-2-yl]oxy]spiro[2-benzofuran-3,9'-xanthene]-1-one
HS Tariff Code	2934.99.9001
Storage	Powder-20°C 3 years 4°C 2 years In solvent -80°C 6 months -20°C 1 month Note: (1). This product requires protection from light (avoid light exposure) during transportation and storage.(2). This product is not stable in solution, please use freshly prepared working solution for optimal results.
Shipping Condition	Room temperature (This product is stable at ambient temperature for a few days during ordinary shipping and time spent in Customs)

Biological Activity

ln Vitro

Fluorescein di(β-D-galactopyranoside) yielded more fluorescein in a dose- and time-dependent manner. The fluorescein di(β-D-galactopyranoside) method yields significantly higher fluorescein levels than the dual substrate method. The method of fluorescein di(β-D-galactopyranoside) yields fluorescein di(β-D-galactopyranoside). In Hs68 cells, the amount of fluorescein generated by galactopyranoside is directly correlated with the passage number [1].

References

[1]. 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.

Solubility Data

Solubility (In Vitro)

DMSO : ~5.56 mg/mL (~8.47 mM)

Solubility (In Vivo)

Solubility in Formulation 1: ≥ 0.56 mg/mL (0.85 mM) (saturation unknown) in 10% DMSO + 40% PEG300 + 5% Tween80 + 45% Saline (add these co-solvents sequentially from left to right, and one by one), clear solution. For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 5.6 mg/mL clear DMSO stock solution to 400 μL PEG300 and mix evenly; then add 50 μL Tween-80 to the above solution and mix evenly; then add 450 μL normal saline to adjust the volume to 1 mL. Preparation of saline: Dissolve 0.9 g of sodium chloride in 100 mL ddH₂ O to obtain a clear solution. Solubility in Formulation 2: ≥ 0.56 mg/mL (0.85 mM) (saturation unknown) in 10% DMSO + 90% (20% SBE-β-CD in Saline) (add these co-solvents sequentially from left to right, and one by one), clear solution. For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 5.6 mg/mL clear DMSO stock solution to 900 μL of 20% SBE-β-CD physiological saline solution and mix evenly. Preparation of 20% SBE-β-CD in Saline (4°C，1 week): Dissolve 2 g SBE-β-CD in 10 mL saline to obtain a clear solution.  (Please use freshly prepared in vivo formulations for optimal results.)

Preparing Stock Solutions		1 mg	5 mg	10 mg
	1 mM	1.5230 mL	7.6151 mL	15.2302 mL
	5 mM	0.3046 mL	1.5230 mL	3.0460 mL
	10 mM	0.1523 mL	0.7615 mL	1.5230 mL

*Note: Please select an appropriate solvent for the preparation of stock solution based on your experiment needs. For most products, DMSO can be used for preparing stock solutions (e.g. 5 mM, 10 mM, or 20 mM concentration); some products with high aqueous solubility may be dissolved in water directly. Solubility information is available at the above Solubility Data section. Once the stock solution is prepared, aliquot it to routine usage volumes and store at -20°C or -80°C. Avoid repeated freeze and thaw cycles.