PRoduct lenght determination - product length determination (Jan/31/2006 )

hi guys i need urgent help on this one

how can you determine product length of a pcr sample. lets say you have a 40 nucleotide sequence, how do you know that all 40 nucleotides will be amplified, esp when the mutation you are interested is sitting in position 35. so in a situation such as this, you need to know that all nucleotides are going to be amplified, but logic shows that you should be able to predict the DNA product length before actually running it against radiolabelled DNA probed molecular weight markers.It would also be a gamble on which markers to run these products against as if your using a 600 bp marker and your product is 710 bp your not going to find?

is there a step to this

I'm not quite sure I understand the question correctly... are you simply asking how one determines the size of a PCR product? If so, this is calculated by most (if not all) primer design programs. Sometimes it is referred to as amplicon length. If it isn't calculated, you can simply match up the forward and reverse primer sequences to the particular region that you're amplifying and do the math.

I apologize if this is not what you are looking for.

-Hank

another question, why are you using radiolabelled markers? I do not understand your application?