Singlet Oxygen Sensor Green^®: Photochemical Behavior in Solution and in a Mammalian Cell

Abstract

The development of efficient and selective luminescent probes for reactive oxygen species, particularly for singlet molecular oxygen, is currently of great importance. In this study, the photochemical behavior of Singlet Oxygen Sensor Green(®) (SOSG), a commercially available fluorescent probe for singlet oxygen, was examined. Despite published claims to the contrary, the data presented herein indicate that SOSG can, in fact, be incorporated into a living mammalian cell. However, for a number of reasons, caution must be exercised when using SOSG. First, it is shown that the immediate product of the reaction between SOSG and singlet oxygen is, itself, an efficient singlet oxygen photosensitizer. Second, SOSG appears to efficiently bind to proteins which, in turn, can influence uptake by a cell as well as behavior in the cell. As such, incorrect use of SOSG can yield misleading data on yields of photosensitized singlet oxygen production, and can also lead to photooxygenation-dependent adverse effects in the system being investigated.

Ubiquity and quantitative significance of detoxification catabolism of chlorophyll associated with protistan herbivory

“…In experiments involving cPPB-aE dissolved in THF, we, therefore, prepared the solution under argon in freshly distilled THF and measured all optical properties immediately. In singlet oxygen detection experiments, generation of singlet oxygen was detected using SOSG (Invitrogen), a commercially available fluorescent probe (52). A chlorophyll derivative (10 μM) and SOSG (1 μM) were dissolved in anisole and methanol (1:1, vol/vol), placed in a quartz cell, irradiated with red light that was provided by a 250 W metal halide lamp (LS-250-7500; Sumita Optical Glass), and passed through a colored glass filter that failed to transmit light with a wavelength shorter than ∼630 nm (AGC Techno Glass).…”

De Novo Generation of Singlet Oxygen and Ammine Ligands by Photoactivation of a Platinum Anticancer Complex

“…SOSG is a highly selective sensor for 1 O 2 without any appreciable response to hydroxyl radicals or superoxide. [9] In the absence of 1 O 2 , SOSG exhibits low fluorescence, but in the presence of 1 O 2 , strong green fluorescence can be observed with l ex = 504 nm and l em = 525 nm. Solutions containing 1 and SOSG were stable in the dark or even upon irradiation at l !…”

Singlet Oxygen Signatures Are Detected Independent of Light or Chloroplasts in Response to Multiple Stresses

“…The SOSG is a twocomponent trap-fluorophore system generating the fluorescent endoperoxide upon specific interaction with singlet oxygen (Gollmer et al, 2011). SOSG is specific for singlet oxygen and will not react with other ROS, including superoxide or H 2 O 2 (Flors et al, 2006).…”

“…The SOSG signal was a yellow fluorescent protein filter (excitation 500 6 10 nm, emission 535 6 15 nm). Because SOSG itself may act as a photosensitizer (Gollmer et al, 2011), low excitation energies were employed. Confocal imaging was conducted with an inverted confocal microscope (Olympus Flow View FV1000) equipped with a UPlanSApo 320 objective (numerical aperture of 0.75) for wound studies and a UPlanSApo 360 oil objective (numerical aperture of 1.35) for localization studies.…”