A Nucleus-Targeting DNA Aptamer for Dead Cell Indication

Area of Science:

• Biotechnology
• Molecular Biology
• Cell Biology

Background:

• Distinguishing dead from live cells is crucial in biological research.
• Current dead cell probes, often nucleic acid intercalators, exhibit low affinity and potential toxicity.
• There is a need for safer, high-affinity probes for accurate cell viability assessment.

Purpose of the Study:

• To develop and characterize a novel aptameric probe for selective detection of dead cells.
• To evaluate the probe's affinity, specificity, and safety compared to existing methods.
• To demonstrate the probe's utility in apoptosis assays and tissue section staining.

Main Methods:

• Generation of the aptameric probe (Ch4-1) using the Cell-SELEX process.
• Characterization of Ch4-1's binding affinity (apparent Kd = 6.65 ± 3.40 nM) to nucleoproteins.
• Assessment of Ch4-1's cell membrane permeability and its selective binding to dead cells.
• Evaluation of Ch4-1's performance in apoptosis assays and nuclear staining of tissue sections.

Main Results:

• Ch4-1 exhibits high affinity binding to cell nuclei (apparent Kd = 6.65 ± 3.40 nM).
• As an oligonucleotide, Ch4-1 does not penetrate intact cell membranes, ensuring selective binding to dead cells.
• Ch4-1 demonstrates no toxicity to live cells and can be easily fluorescently labeled.
• The probe successfully distinguished dead from live cells in apoptosis assays and stained tissue sections.

Conclusions:

• The novel aptameric probe Ch4-1 offers a high-affinity, non-toxic method for dead cell detection.
• Ch4-1 overcomes limitations of traditional probes, enhancing accuracy in cell viability studies.
• This probe shows significant potential for applications in apoptosis analysis and histological staining.