Over the past six months, we have made substantial progress towards development of biologically-active reversible terminators. The discovery of a new class of modified nucleosides has established the foundation for development of a four-color reversible terminator set in the near future. Still, tremendous work is required in organic synthesis, compound modeling, and UV deprotection to move the technology from the stage of feasibility to practical application. We are requesting supplemental funding to accelerate our progress for developing the ultra-fast DNA sequencing strategy. Here, we present our recent progress on the development of our first dye-labeled, reversible terminator and step-wise sequencing through a homopolymer repeat. Additional research goals are proposed to deliver a four-color, reversible terminator nucleotide set within the next 12-18 months for implementation of the cyclic reversible termination (CRT) sequencing platform. ? ? ? ?