[thedy]

Hi,in my book is written,that when we try to determine large mutations with hybridization probes,we do not need two probes.But,if we have small(short)mutations we need two probes,one with mutant sequence and the second one with normal sequence.Why is it so?Why we need two probes to determine small mutations?Because,correct me if I am wrong,if we have mutant only one nucleotide,complementary probe show us mutation and we know that something is wrong,Why do we need control probe also?And why only in shor mutations?
Thanks a lot....I am stucked

[rjb]

Thedy,

In this case the answer that you're looking for is perhaps embedded in the question that you posed. I shall pose a couple of my own which might help get you thinking along what I think are the right lines...

If you've designed a larger more complex probe to detect your mutant allele, is your probe likely to bind at some other (unrelated/non-specific) point on the genome?

If you designed a considerably smaller probe, is it more or less likely to bind to some other (unrelated/non-specific) point on the genome? If so, what are the consequences? How could you circumvent this and show that the mutation was genuine rather than a non-specific binding event?

Hope this helps.

R