Related Experiment Videos
Observation of DNA molecules undergoing capillary electrophoresis
1Cell and Molecular Biology Division, Lawrence Berkeley Laboratory, Berkeley, CA 94720.
Journal of Biomolecular Structure & Dynamics
|December 1, 1991
Summary
This study visualizes large DNA molecule movement during capillary electrophoresis (CE). DNA mobility is constant at high electric fields but increases at low fields, forming aggregates at very high fields.
Area of Science:
- Biophysics
- Molecular Biology
- Analytical Chemistry
Background:
- Capillary electrophoresis (CE) is a powerful separation technique.
- Observing large DNA molecule behavior in CE requires specialized methods.
- Understanding DNA dynamics under electric fields is crucial for molecular analysis.
Purpose of the Study:
- To develop a method for observing large DNA molecule motion and configuration during capillary electrophoresis.
- To investigate the relationship between electric field strength and DNA mobility.
- To characterize the behavior of DNA molecules at varying electric field strengths.
Main Methods:
- Designed a horizontal capillary electrophoresis device for microscopic observation.
- Utilized epi-fluorescence microscopy to image single DNA molecules within the capillary.
- Measured the electrophoretic mobility of T4, lambda bacteriophage, and PBR322 plasmid DNA at different electric field strengths.
Main Results:
- DNA molecules migrated towards the negative electrode under an applied electric field.
- DNA mobility remained constant at high electric fields (200-600 V/cm) and increased at low fields (<50 V/cm).
- Apparent DNA mobilities were independent of molecular weight, and aggregates formed at high fields (>400 V/cm).
Conclusions:
- The study provides a novel method for visualizing DNA dynamics in CE.
- DNA mobility exhibits distinct behaviors at low and high electric field strengths.
- The formation and dissociation of DNA aggregates offer insights into molecular interactions under electric fields.