I need to do PCR on human cell genomic DNA, very small amount (around 5000 cells) that were frozen in 500ul QIAGEN RLT buffer (not that I could do anything about that).
Now RLT is proprietary, but supposedly contains a high concentration of guanidine isothiocyanate and some other nasty things.
My original idea was just lyse the cells by heating and just put into PCR, howevrer I got most of them in Trizol (isolation required) or RLT. I can isolate from Trizol thought that is a pain in the ass with DNA and the small number of cells is problematic (I've done that before, but repeatedly thought of better way to do that), but I can't even use any standard isolation protocol from RLT and some Q colums I have, because it's generaly designed for RNA isolation. In addition, elution volumes from columns are to high. I'm kind of affraid I wouldn't get any DNA, from whole volume used (which I idealy should not use whole).
So I'm thinking of some quick way how to get PCR-suffucient DNA out of the RLT solution, or at least minimize the guanidine content. Pelet the lysate on high g (if possible) and take the GITC out? Compensate the PCR reaction for GITC and use only a very small amount?
Any other ideas?