Project Summary Electronic BioSciences (EBS) will investigate and develop methodologies to sequence microsatellite regions within the human genome to enable cancer genotyping via a true single-molecule, ultra-high-accuracy approach. Microsatellites are simple/short repeats (1-10 nucleotides in length) that occur in tandem 5-50 times and are among the most variable types of DNA sequence in the genome. Mutations to these microsatellite regions, or what is referred to as microsatellite instability (MSI), includes expansion or contraction of the repeat number, single nucleotide polymorphisms (SNPs), and/or insertions or deletions (indels), which have been documented with all current types of cancer. Unfortunately, current sequencing technologies, including both next generation sequencing (NGS) and third generation sequencing (TGS), are not capable of sequencing microsatellites and MSI with any sort of clinically relevant accuracy or precision due to limitations with the methodology utilized, which has significantly hindered the understanding of these types of sequences. During this Phase I SBIR program, EBS will focus on developing a new platform and sequencing approach specifically aimed at microsatellites. The investigations performed during this program will enable new approaches to probe microsatellites, MSI and the human genome in general, directly improving basic cancer research and ultimately enabling vastly improved clinical diagnostics and/or prognostics technologies.