A graduate student is digesting a 4600 base pair long plasmid, with restriction sites at the following locations: 200, 500, 1100, 2300, and 4500. After digestion is complete, she loads these fragments in a well of an agarose gel. She is also loading several other DNA digests in the same gel (including the undigested plasmid) in different wells. After the gel is ready, she cannot remember which well she loaded the plasmid digest.
How can she tell which is the correct lane containing the fragments of interest?