Figure 3.

(A) As a negative internal control, in vitro synthesized (CAG)800•(CTG)800 DNA (MATERIALS & METHODS) were completely methylated at all 5′-GpC-3′ sites by DNA 5-cytosine methyl-transferase M.CviPI (indicated by +) and mixed at equimolar amounts with in vitro synthesized (CAG)500•(CTG)500 DNA that were mock-treated with M.CviPI GpC methylase (indicated by −). These DNA mixtures were restriction digested with Fnu4HI and products resolved by electrophoresis on 1% agarose gels. The 100 bp ladder was loaded in the leftmost lane. (B) In vitro synthesized (CAG)800•(CTG)800 DNA was mock-treated with GpC methylase (−) or methylated (+) at all GpC sites. The DNA was restriction digested with BbvI, MwoI, TseI, ApeKI or EcoP15I and products resolved by electrophoresis on 1% agarose gels. DNA marker has been loaded in the leftmost lanes.