We describe ultra-high throughput polony genome sequencing that can permit, for example, generating raw data to re-sequencing the human genome in about one week (including library prep and sequencing) at a reasonable cost. The methods described herein include one or more of the following: (1) increasing polony sequencing read length, (2) improving library construction and emulsions protocols, (3) increasing bead density and/or moving to alternative clonal amplication strategies (other than emulsion PCR or ePCR), (4) extending software capabilities to allow SNP calls from our new sequencing raw data, (5) Dual Primer Emulsion PCR, and (6) diagnostic method exploiting one or more of the foregoing.