Phen Green SK diacetate (5/6-mixture)  (Synonyms: PGSK diacetate (5/6-mixture))

Phen green SK (PGSK) diacetate (PGSK diacetate (5/6-mixture)) is a metal ion-sensitive fluorescent probe that can penetrate cell membranes. Phen green SK (PGSK) diacetate can react with a variety of metal ions, including Fe²⁺, Cd²⁺, Co²⁺, Ni²⁺, Zn²⁺, etc. Phen green SK (PGSK) diacetate chelates Fe²⁺, resulting in fluorescence quenching, which can be restored when a membrane-permeable chelator is added, thereby reflecting the changes in the intracellular chelatable iron pool. The excitation/emission maxima of Phen green SK diacetate are 507/532 nm, respectively^[1][2][3].

Phen Green SK diacetate (5/6-mixture) (20 μM; 10 min) chelates Fe²⁺ in rat hepatocytes, resulting in fluorescence quenching. However, fluorescence was restored after the addition of 5 mM 2,2'-Dipyridyl^[1].
The fluorescence of Phen Green SK diacetate (5/6-mixture) (20 μM; 10 min) in human erythroleukemia K562 cells was quenched by 10 μM Fe(III)-8-Hydroxyquinoline (HY-B1005) complex, and the iron concentration in K562 cells was measured to be 4.0 μM^[1].

Phen Green SK diacetate (5/6-mixture) is used to detect intracellular Fe²⁺ levels^[2][3]:
(1) Wash the target cells (e.g., HepG2 and Huh7 cells^[2], H9C2 cells^[3]) with phosphate-buffered saline (PBS) and incubate with Phen Green SK diacetate (5/6-mixture) at 37°C in the dark (the appropriate concentration for HepG2 and Huh7 cells is 20 μM, 20 min; the appropriate concentration for H9C2 cells is 10 μM, 30 min).
(2) After washing the cells again, suspend the cells in PBS and use them for flow cytometry analysis.

Phen Green SK diacetate (5/6-mixture) can be used in conjunction with the lipid peroxidation indicator dye BODIPY 581/591 C11 (HY-D1301) to assess the ferroptosis state of cells^[3].

Effects of different metal and nonmetal ions on the fluorescence of Phen Green SK diacetate (5/6-mixture) in a cell-free system (spectrofluorimetry)^[1]:
(1) PG SK (50 μM) was dissolved in Chelex-treated medium (pH 7.2, 37°C) designed to mimic the composition of cytosol. (2) Baseline fluorescence was recorded for 5 min (excitation wavelength: 488 nm; emission wavelength: 520 nm). (3) The corresponding salt ions were added and quickly mixed with the medium in the cuvette. The relative emission intensity was expressed as a percentage of the baseline fluorescence intensity (set to 100%).
Results show^[1]:

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

706.48

C₃₇H₂₁Cl₂N₃O₈

234075-45-7

Solid

Light yellow to yellow

532

507

O=C(C1=CC2=C(C3(C4=C(OC5=C3C=C(Cl)C(OC(C)=O)=C5)C=C(OC(C)=O)C(Cl)=C4)OC2=O)C=C1)NC6=C7C=CC=NC7=C8N=CC=CC8=C6.CC(OC(C(Cl)=C9)=CC%10=C9C%11(C%12=C(C(O%11)=O)C=CC(C(NC%13=C%14C=CC=NC%14=C%15N=CC=CC%15=C%13)=O)=C%12)C(C=C%16Cl)=C(O%10)C=C%16OC(C)=O)=O

Shipping with dry ice.

-80°C, protect from light, stored under nitrogen

* Please refer to the solubility information to select the appropriate solvent. Once prepared, please aliquot and store the solution to prevent product inactivation from repeated freeze-thaw cycles.
Storage method and period of stock solution: -80°C, 6 months (protect from light, stored under nitrogen). When stored at -80°C, please use it within 6 months.

• [1]. Petrat F, et al. Determination of the chelatable iron pool of isolated rat hepatocytes by digital fluorescence microscopy using the fluorescent probe, phen green SK. Hepatology. 1999;29(4):1171-1179.  [Content Brief]

  [2]. Li L, et al. NDRG1 alleviates Erastin-induced ferroptosis of hepatocellular carcinoma. BMC Cancer. 2025 Mar 21;25(1):522.  [Content Brief]

  [3]. Xu Z, et al. Total extracts from Abelmoschus manihot (L.) alleviate radiation-induced cardiomyocyte ferroptosis via regulating redox imbalances mediated by the NOX4/xCT/GPX4 axis. J Ethnopharmacol. 2024 Nov 15;334:118582.  [Content Brief]