PCR... please help?

Question

if the amplified product of pcr contains an invariant Alul site. How is the presence of this site an advantage for genetic diagnosis of the mutation?

Answer 1

Umm... if memory serves, that allows you to use Alu I to then cut the amplified fragments to check for their lengths; this can pick up insertions and deletions. In theory it would also allow you to pick up mutations in the Alu I site itself, but this probably isn't all that useful unless the Alu I site is a hotspot.

Answer 2

Hard to answer that without knowing what the mutation is. Is it a nucleotide change in the Alu recognition site that would stop the enzyme from cutting? Is it an addition or deletion elsewhere in the product that would change the size of the fragment(s)? Inquiring minds want to know!

Answer 3

It means you can run a genetic test with PCR with an extra degree of accuracy. Compared to just running the PCR and looking at the length, you can perform an AluI digest on the purified PCR product to further verify your target.

This digest is much faster and cheaper to do than sequencing. (Though sequencing is still the gold standard.)

Answer 4

PCR using a primer that anneals to Alu repeats to amplify DNA located between two oppositely oriented Alu sequences. I guess its advantage because it repeats the the cycle...