Internal Control RNA or DNA - (Mar/17/2011 )

Hi..

Can anyone please enlighten me with the function of internal controls used for nucleic acid purification/isolation.

Thank you..

In simple, to tell that your amplification(PCR) is working although there is negative result(no amplicons, except the internal control).

Thank you soo much.

Also can you please help me with the difference between Carrier RNA and Carrier DNA and also there function (or sequence if you can help me with) .
Actually I have been using some kits for DNA isolation and purification, where in one kit, they are recommending the use of carrier DNA and in the other, carrier RNA.
Both are for DNA isolation, then why is this difference there?

what kit is that? Brand, model? Catalog?

Its Qiagen's kit for DNA purification.
QIAamp DNA Mini kit where they are recommending the use of Carrier DNA when the sample is low copy and
another kit is QIAamp DNA Micro Kit where they are recommending the use of Carrier RNA.