Fluorescein sodium salt (CAS 518-47-8) is a disodium salt of fluorescein and a noted pH sensitive fluorophore. Fluorescein sodium salt has been utilized in studies as a drug model, as a penetrating dye and also as a fluorescein tracer. Fluorescein sodium salt has also been used in vitro to quantify root dentin demineralization. Additional reported uses include microscopy, as a gain medium in dye laser use and to detect latent blood stains in vitro. Common derivatives of Fluorescein include fluorescein isothiocyanate (FITC), eosin and Rose Bengal (sc-296278) and Rose Bengal sodium salt (sc-203757)
Synonym: Acid Yellow 73

Appearance : Powder
Physical State : Solid
Solubility : Soluble in water (500 g/l) at 20° C, ethanol (slightly soluble),Insoluble in benzene, chloroform, ether. Soluble in glacial acetic acid; also soluble in alkali hydroxides or carbonates with a bright green fluorescence appearing red by transmitted light.
Storage : Store at room temperature
Melting Point : >300° C
Boiling Point : 662.6° C at 760 mmHg (Predicted)
Fluoresence : λex 490 nm, λem 514 nm in 0.1 M Tris pH 9.0
pK Values : pKa: 4.40 (Predicted)
RTECS : LM5425000
PubChem CID : 10608
Merck Index : 14: 4159
MDL Number : MFCD00167039
EC Number : 208-253-0
Beilstein Registry : 3833041
Molecular Weight:376.27