Data transformation and bisulfite validation. (a) Scatter plot showing the relationship between the number of HpaII and MspI reads at each locus. (b) The location of the data point on the scatter plot indicates whether it is likely to be less or more methylated with larger or smaller angles B subtended as shown, while the confidence of the measurement will be greater when more reads represent the data point, represented by the length of line c. (c) The HpaII count correlates negatively with the degree of methylation, with more counts occurring at loci with less methylation. (d) Transformation of the data to the B angle measure to normalize HpaII by MspI counts substantially improves the correlation with bisulfite MassArray validation data.
Suzuki et al. Genome Biology 2010 11:R36 doi:10.1186/gb-2010-11-4-r36