New Assays for Methylation Patterns in Cancer

The Genomic Walking strategy is currently the only sequencing method sensitive to methylationpatterns and thus should be used to detect methylated residues. The current implementation of the GWstrategy is limited by the sensitivity of the autoradiography used to image the sequencing blots (about10[-17] moles per sequencing band). The use of a spatially resolving MPD system (that has a provenresolution of 10[-20] moles) to resolve the sequencing ladders produced by the GW strategy would allowthe survey of the methylation patterns as well as the analysis of sequence of genes in linkage analysis.There is one instrumental and one biochemical objective that we plan to address in this proposal: *development of multilabel imager with spatial resolution better than 100 microns and sensitivity of10[-20] moles; * imaging human genomic sequencing blots to identify methylated residues anddetermine the dynamic range of the methylation patterns.