Making DNA hybridization assays in capillary electrophoresis quantitative

Area of Science:

• Molecular Biology
• Biochemistry
• Analytical Chemistry

Background:

• Gel-free capillary electrophoresis offers efficient separation of hybridization probes.
• Single-stranded DNA-binding protein (SSB) facilitates probe-hybrid separation by altering probe mobility.
• Quantitative analysis of SSB-mediated hybridization assays requires addressing label quenching and hybrid dissociation.

Purpose of the Study:

• To develop a general approach for quantitative SSB-mediated hybridization analysis.
• To investigate the influence of probe-target hybridization and SSB binding on fluorescent label quantum yield.
• To experimentally determine if SSB dissociates probe-target hybrids.

Main Methods:

• Utilized capillary electrophoresis with SSB in the run buffer.
• Employed fluorescently labeled probes for real-time detection.
• Quantified hybridization signals while accounting for potential quenching and dissociation effects.

Main Results:

• Developed a quantitative framework for SSB-mediated hybridization analysis.
• Demonstrated that SSB binding does not significantly affect the quantum yield of the fluorescent label.
• Provided the first experimental evidence that SSB does not dissociate probe-target hybrids.

Conclusions:

• SSB-mediated hybridization analysis can be made quantitative without calibration curves.
• The absence of SSB-induced hybrid dissociation simplifies quantitative interpretation.
• This method enhances the utility of SSB in sensitive, real-time hybridization assays.