Research on the Effect of Electric Field Strength on DNA Capillary Electrophoresis

Capillary electrophoresis(CE) has become an essential technique for the analysis of biomolecules such as DNA. The strength of the applied electric field plays a critical role in determining the outcomes of capillary electrophoresis experiments. This study employs a lab-built capillary electrophoresis system to detect fluorescent signals generated by the binding of DNA with SYBR Green I using a lab-assembled photomultiplier tube (PMT) circuit. Electrical signals were recorded and transmitted to a terminal device via a data acquisition card, producing waveform diagrams for analysis. The study investigates the capillary electrophoresis results of a 100 bp DNA ladder containing six fragments under varying electric field strengths. Key parameters such as DNA migration time, migration rate, and resolution were analyzed. The findings indicate that higher electric field strengths result in faster DNA migration times but reduced separation resolution. These results provide valuable insights for optimizing DNA capillary electrophoresis protocols.