Storage Condition ： Store at 0-5^oC and protect from light

Product Description
Singlet oxygen (¹O₂) is one of the Reactive Oxygen Species (ROS). ¹O₂ is known to be a cause of spots and wrinkles of the skin due to its very strong oxidizing potential. In the field of cancer research, ¹O₂ is of a particular importance because of its key role in photodynamic therapy (PDT), an emerging anticancer treatment using photoirradiation and photosensitizers. For the detection of ¹O₂, the existing singlet oxygen fluorescence detection reagent cannot be used in living cells because of its cell membrane impermeability.
Majima et al. synthesized a new far-red fluorescence probe composed of silicon-containing rhodamine and anthracene moieties, namely Si-DMA, as a chromophore and a ¹O₂ reactive site, respectively. In the presence of ¹O₂, fluorescence of Si-DMA increases 17 times due to endoperoxide formation at the anthracene moiety⁽¹⁾,⁽²⁾. Among seven different ROS, Si-DMA is able to selectively detect the ¹O₂ (Fig. 3). In addition, Si-DMA is able to visualize the real-time generation of ¹O₂ from protoporphyrin IX in mitochondria with 5-aminolevulinic acid (5-ALA), a precursor of heme(Fig. 4).



Usage Example
Fluorescence microscopic detection of ¹O₂ in HeLa cells after added 5-aminolevulinic acid (5-ALA)

1. HeLa cells (2.4×10⁵ cells/ml, Hanks’ HEPES buffer 200 μl) were seeded on a μ-slide 8 well (Ibidi) and cultured at 37 ^oC in a 5%CO₂ incubator overnight.
2. Cells were washed with 200 μl Hanks’ HEPES buffer twice.
3. 150 μg/ml of 5-ALA in Hanks’ HEPES buffer was added to the μ-slide and cultured at 37 ^oC in a 5%CO₂ incubator for 4 hours.
4. Cells were washed with 200 μl Hanks’ HEPES buffer twice.
5. 200 μl of Si-DMA working solution (40 nmol/L) was added and cultured at 37 ^oC in a 5%CO₂ incubator for 45 minutes.
6. Cells were washed with 200 μl Hanks’ HEPES buffer twice.
7. 200 μl Hanks’ HEPES buffer was added and observe the cells under a fluorescence microscope.

Fluorescent of Si-DMA in 5-ALA-treated HeLa cells increased after 2.5 minutes irradiation. It was found that Si-DMA was able to visualize in real time the ¹O₂ generated from protoporphyrin IX in mitochondria.