Conjugated Oligoelectrolyte with DNA Affinity for Enhanced Nuclear Imaging and Precise DNA Quantification

Area of Science:

• Biochemistry
• Molecular Biology
• Cell Biology

Background:

• Accurate DNA quantification and imaging are essential for diagnostics and drug discovery.
• Mitochondrial DNA detection indicates cellular health.
• Novel fluorescent probes are needed for precise DNA analysis.

Purpose of the Study:

• To develop and characterize a novel conjugated oligoelectrolyte (COE) molecule, COE-S3, for DNA quantification and cellular imaging.
• To evaluate COE-S3's fluorescence properties, DNA binding affinity, and cellular localization.

Main Methods:

• Synthesis and characterization of COE-S3.
• Spectroscopic analysis of fluorescence properties (quantum yield, Stokes shift).
• DNA binding studies using intercalation mode and determination of binding constant.
• Cellular imaging in living and apoptotic cells to assess localization and vitality.

Main Results:

• COE-S3 exhibits high water solubility, quantum yield (0.79), and a significant Stokes shift.
• COE-S3 demonstrates specific and proportional fluorescence response to DNA concentration.
• It binds to double-stranded DNA (dsDNA) with a high binding constant (1.32 × 10^6 M^-1) via intercalation.
• COE-S3 localizes in mitochondria of living cells and nuclei of apoptotic cells, enabling real-time vitality assessment within 30 min.

Conclusions:

• COE-S3 is a promising fluorescent probe for quantitative intracellular DNA analysis.
• Its unique amphiphilic structure and DNA affinity facilitate targeted cellular localization.
• COE-S3 enables rapid assessment of cell vitality and provides insights into cellular processes like proliferation and differentiation.