Unpurifed DNA for methylation - (Aug/08/2005 )

I did some Genomic extraction by using Qiagen Mini Kit, and a lot of samples have the A260/A280 values which are around 1.2. That means my DNA have a lot of contaminants such as RNA and Protein. Does anybody think that would affect the MSP results? Since I am getting weak bands and strong dimers which is not allowed in SYBR real timer PCR.

yes they certainly affect bisulfite conversion efficency.

is it possible to further purify the DNA with a phenol clhoroform step, precipitate and resuspend for bisulfite conversion.

It is known that protein and RNA contamininants reduce the efficency of the bisulfite conversion reaction.

Nick