Question

Why is a marker used when running the fragments through the agarose gel electrophoresis ?

Answer 1

ANSWERS

Gel electrophoresis is technique that uses agarose gels ,which helps to visualise fragments of DNA to  separate DNA fragments and other macromolecules by size and charge.

• A marker containing DNA fragments of known size is loaded into the first well of the gel.
• The fragments in the marker are of a known length so can be used to help to identify the size of the fragments in the samples.
• It is run through every gel for comparison with the unknown fragments in other gel lanes.
• It also shows where restriction enzymes cut the original piece of DNA.