live cell imaging system

Dehydroergosterol is a fluorescent cholesterol analog (Ex/Em = 325/375 nm) used in cholesterol transport, membrane structure research, and live-cell imaging. Unlike cholesterol, Dehydroergosterol contains three additional double bonds, an extra methyl group, and an ergosterol side chain, forming a conjugated system that produces intrinsic fluorescence. In its monomeric form, Dehydroergosterol exhibits excitation peaks at 310-311, 324, and 338-340 nm, as well as emission peaks at 354, 371-375, 390-394, and 414 nm; in its microcrystalline form, Dehydroergosterol shows enhanced excimer emission around 404 and 426 nm. Dehydroergosterol mimics the properties of cholesterol, integrates into membranes and lipoproteins, and localizes to organelles .

NtHzBtd is a fluorescent probe for detecting Fe ³⁺. NtHzBtd is applicable to the selective fluorescent detection of Fe ³⁺ ions and live cell imaging studies. NtHzBtd can selectively coordinate with Fe ³⁺ to form a 1:1 complex, triggering chelation enhanced quenching (CHEQ) and intramolecular charge transfer (ICT) processes, which result in fluorescence turn-off, thereby enabling sensitive detection of Fe ³⁺ and live cell fluorescence imaging. After binding to Fe ³⁺, NtHzBtd reduces fluorescence intensity, exhibits a rapid response property, with a limit of detection of 0.036 μM and a response time of approximately 55 s. The detection wavelengths are Ex/Em = 334/401 nm (solution system) .

Mito-RhFe is a Fluorescent probe for mitochondrial labile Fe³⁺ monitoring via imaging and flow cytometry. This probe is a rhodamine-based construct with a spirolactam fluorescence signaling group and an N2-hydroxyethyldiethylenetriamine chelator; its delocalized positive charge enables mitochondria-targeting ability in live cells, and it exhibits fine cell membrane permeability. In its native state, it exists in the non-fluorescent spirolactam form, but upon binding to Fe³⁺, it undergoes a ring-opening conversion to the fluorescent rhodamine form, triggering a turn-on fluorescent response; this process is reversible, as the addition of the metal chelator TPEN removes Fe³⁺ and converts the probe back to its non-fluorescent spirolactam form, and re-addition of Fe³⁺ restores fluorescence. The probe shows high selectivity for Fe³⁺ over most other metal cations present in living systems, with a ~90-fold fluorescence enhancement upon binding to 20 equiv of Fe³⁺. Mito-RhFe has excitation/emission wavelengths of Ex/Em = 540/578 nm, with an ~8 nm bathochromic shift in emission upon Fe³⁺ binding, and it can also be excited at 543 nm for confocal imaging with emission detected at 570-620 nm[1].