Figure 2b: Methylation Specific Analysis after bisulfite treatment. Presence of two novel strands provides different templates for either methylation specific PCR or sequencing. Following fragment analysis allows for the characterization of the X- inactivation pattern. In the case of random X-Inactivation two peaks will be observed in heterozygous females while, if non random skewed X-inactivation has occurred differences in size ratios of the heterozygous peak patterns will be noticed.