Biology 12: RFLP, How it works

what is a probe

a DNA or RNA molecule with a base sequence complementary to a sequence in the gene of interest

how big are probes

short sections

when we run the DNA fragments we run the ones that have what

the probe attacted

explain how we can determine if there is mutantions

Normal gene has 3 recognition sites

Mutanted gene haas 2 recognition sites

The enzyme will cut the normal gene at the 3 sites, in this example it will make cuts closer to the probe, meaning the fragment the probe is on will be much smaller

The mutanted DNA will be cut only twice, and further from the probe. Meaning the fragment containing the probe will be much bigger.

Because the fragment is bigger it will travel slower, meaning we can tell if a gene is mutanted if the DNA fragmen travels slower through the gel.