In particular, the modified spirolactam structure which enables colorless and nonfluorescent
can be transformed into the colored and highly fluorescent ring-opened amide form in the presence of the corresponding metal ions .
Calcein AM (495/515 nm absorption/emission) and calcein violet (400/452 nm) are both membrane permeable and nonfluorescent
, requiring hydrolysis to be converted into a membrane-impermeable fluorescent analog (11, 16).
The TaqMan[R] probe, which contained a 5' reporter dye and a 3' nonfluorescent
quencher, was used for RT-PCR.
Nitroaromatics are electron deficient in nature; due to this reason some electron-rich fluorescent probes can always produce nonfluorescent
Meisenheimer or [pi]-stacking complexes with nitroaromatics [11,12].
This assay relies on the principle that, after diffusion into the cell, DCFDA gets deacetylated by cellular esterases to a nonfluorescent
compound, which is later oxidized by ROS into 2',7'-dichlorofluorescein (DCF).
Epithelial cells inside acinus are distinctly observed based on the fluorescent cytoplasm and nonfluorescent
normal BJ and sBJ cells from cocultures were also isolated simultaneously for Western blot experiments.
Neonicotinoids are nonfluorescent
or slightly fluorescent compounds.
The ion-responsive mechanism was achieved due to the well-known equilibrium between the nonfluorescent
spirolactam and the fluorescent ring-opened amide of rhodamine.
The assay uses the cell-permeable fluorogenic probe 2',7'-dichlorodihydrofluorescein diacetate (DCFHDA), which upon diffusion into cells is deacetylated by cellular esterases to form a nonfluorescent
compound that is then rapidly oxidized by ROS to create highly fluorescent 2',7'-dichlorodihydrofluorescein (DCF).
The probe is labeled with a dye and a nonfluorescent
quencher FAM reporter.
Dynamic quenching was caused by the fluorescent chromophore interacted with a quencher in excitation state, while the causes of static quenching were of three types: the first one, the fluorescent chromophore interacted with a quencher in ground state and came into being a nonfluorescent
compound; the second one, the medium near the fluorescent chromophore had a polarity change, which caused by the conformational change of the protein attributing to the combination with the quencher; and the third one, a radiationless energy transfer between the fluorescent chromophore and the quencher .