Ratiometric Fluorescence Imaging for the Distribution of Nucleic Acid Content in Living Cells and Human Tissue Sections

Abstract

The misregulation of nucleic acids behavior leads to cell dysfunction and induces serious diseases. A ratiometric fluorescence probe is a powerful tool to study the dynamic behavior and function relationships of nucleic acids. However, currently, no such effective probe has been reported for in situ, real-time tracking of nucleic acids in living cells and tissue sections. Herein, the unique probe named QPP-AS was rationally designed for ratiometric fluorescence response to nucleic acids through skillful regulation of the intramolecular charge-transfer capabilities of the electron acceptor and donor. Encouraged by the advantages of the selective nucleic acid response, ideal biocompatibility, and high signal-to-noise ratio, QPP-AS has been applied for in situ, real-time ratiometric fluorescence imaging of nucleic acids in living cells for the first time. Furthermore, we have demonstrated that QPP-AS is capable of visualizing the dynamic behavior of nucleic acids during different cellular processes (e.g., cell division and apoptosis) by ratiometric fluorescence imaging. More significantly, QPP-AS has been successfully used for ratiometric fluorescence imaging of nucleic acids in human tissue sections, which provides not only the cell contour, nuclear morphology, and nuclear–plasma ratio but also the nucleic acid content information and may greatly improve accuracy in clinicopathological diagnosis.

Cellular and Intravital Imaging of NAD(P)H by a Red-Emitting Quinolinium-Based Fluorescent Probe that Features a Shift of Its Product from Mitochondria to the Nucleus

“…These results highlight that NADH-RH is a novel nucleus-directed dye. The driving force for nucleus-targeting of NADH-RH may lie in its strong binding with DNA through its fitting well in the minor groove of DNA based on its flexible and rotatable D (donor)−π–A (acceptor) structure and its noncovalent interactions with DNA, including possible electrostatic interaction, hydrogen bond, and π–π stacking. , Further investigations on the binding of NADH-RH with DNA are currently underway in our group. Currently, red nucleus-directed dyes remain to be relatively scarce, and the finding of NADH-RH should thereby be of concern for designing new nucleus-targeting fluorescent probes and drugs.…”

Thiophene and diaminobenzo- (1,2,5-thiadiazol)- based DAD-type near-infrared fluorescent probe for nitric oxide: A theoretical research

“…Therefore, there is an urgent need to develop NO imaging probes with high sensitivity, high specificity, and high spatial and temporal resolution for the real-time detection of NO in vivo so as to further improve the diagnosis and treatment of IBD ( Weissleder and Ntziachristos, 2003 ; Sasaki et al, 2005 ; Yu et al, 2012 ; Vegesna et al, 2013 ; Zhang et al, 2017 ). A near-infrared (NIR) fluorescent probe has more advantages in non-invasive imaging in vivo , which can further enhance the penetration of deep tissue and improve the signal-to-noise ratio ( Antaris et al, 2016 ; Hong et al, 2017 ; Liu et al, 2021a ; Wang et al, 2021 ; Xu et al, 2021 ). However, the current small-molecule fluorescent probes used for NO detection still have shortcomings such as short wavelength (<700 nm) and poor water solubility, especially in deep tissue and disease animal models.…”

PET/d-PET (PdP) Pairing for the Design of Dual-Channel Probes

“…First, when the two fluorophores are placed far apart, ground-state or excited-state interactions in between are inhibited. An internal-reference type signal − is expected from such a distant dye pair. Second, when in appropriate proximity, two fluorophores could interact through excited energy transfer (EET) of Dexter type or Föster type. − Ratiometric probes are routinely developed with EET pairing of fluorophores. − To facilitate EET, the HOMO of the donor should be lower and the LUMO of the donor should be higher than the HOMO and the LUMO of the acceptor, respectively (Figure a).…”