Microfluidic Capillary Electrophoresis for Fragment Sizing of PCR Products: A Microchip-Based Electrophoretic Separation Technique to Separate DNA Fragments Based on Size

Microfluidic electrophoresis is a technique to separate different-sized DNA fragments within microcapillaries.

To begin, take a multi-well microfluidic chip having designated wells for the mixture of gel-based polymer and fluorescent dye, DNA samples, and a known molecular-weight DNA ladder. These wells are interconnected via a network of microchannels.

Dispense gel-dye mix into allocated wells. Assemble the chip on a priming station pre-fitted with an empty syringe. Press down the syringe plunger, applying pressure to force the gel-dye mix into the separation microchannel.

Remove the chip and pipette other components into their respective wells. Add a marker - an internal standard that calibrates the sample sizing - to the wells containing the ladder and samples.

Insert the microchip into a fragment analyzer to run the chip. Once inside, the applied voltage generates electrophoretic forces, driving the sample from the well into the sample-loading microchannel from where it reaches the cross-intersection between this channel and the separation channel. The electric current helps the sample enter the separation microchannel.

The fluorescent dye molecules intercalate negatively charg