Pulsed Field Gel Electrophoresis Concepts

The video tutorial introduces gel electrophoresis, a technique for separating DNA fragments based on size. It highlights the limitations of conventional agarose gel electrophoresis, particularly for DNA fragments around 15 KB, which travel the same distance. To address this, pulsed field gel electrophoresis was developed, applying an alternating electric field at an angle, causing DNA fragments to move in a zigzag pattern. This allows for the separation of larger DNA fragments, although it takes several hours compared to the 20 minutes required for conventional methods.

What is the primary purpose of pulsed field gel electrophoresis?

• To separate proteins based on charge

• To separate chromosomes and large DNA fragments

• To amplify DNA sequences

• To measure the concentration of DNA

What is a key characteristic of the agarose gel used in conventional electrophoresis?

• It is made of silicon

• It is a porous gel

• It is non-porous

• It is electrically conductive

Why do large DNA fragments travel shorter distances in conventional agarose gel electrophoresis?

• They are heavier

• They are less charged

• They are more easily oriented

• They encounter more resistance

What problem does pulsed field gel electrophoresis solve?

• Separating small DNA fragments

• Separating proteins

• Separating large DNA fragments that travel the same distance

• Amplifying DNA sequences

How is the electric field applied in pulsed field gel electrophoresis?

• At a constant angle of 90 degrees

• At a fixed angle of 45 degrees

• At an angle of 120 degrees

• At a variable angle of 180 degrees

What movement pattern do DNA fragments follow in pulsed field gel electrophoresis?

• Zigzag

• Straight line

• Circular

• Random

Why do larger DNA fragments take longer to orient themselves in pulsed field gel electrophoresis?

• They are heavier

• They take longer to adjust to the changing electric field

• They are more complex

• They are less charged

How long does pulsed field gel electrophoresis typically take to complete?

• 20 minutes

• Several hours

• One day

• A few seconds