tokens: Both the unmethylated - and methylated - specific PCRs were performed in 50 micro l reaction mixes containing 2 . 5 U AmpliTaq Gold DNA Polymerase ( Applied Biosystems ) , 1 x PCR buffer , 1 . 5 mM MgCl2 , 0 . 1 mM of each deoxynucleotide triphosphate , 0 . 2 micro M of each primer ( Table 1 ) and 2 micro l of modified genomic DNA .