The PCR products from the aforementioned reactions were resolved on a 2% agarose gel and visualized under an UV illuminator (BioDoc Analyzer, Biometra; Analytik Jena, Jena, Germany) using a 100 bp DNA size ladder. To establish the degree of methylation from qualitative MSP data, the change in methylation (Δ meth) value was calculated, as previously described (25 (link),26 (link)). The Δ meth value was calculated by subtracting the un-methylation values of a particular sample from its methylation values, when considering un-methylation as the default condition.