A brass-platinum electrochemical micro flow cell was developed to extract [18F]fluoride from an aqueous solution and release it into an organic based solution, suitable for subsequent radio-synthesis, in a fast and reliable manner. This cell does not suffer electrode erosion and is thus reusable while operating faster by enabling increased voltages. By optimizing temperature, trapping and release potentials, flow rates, and electrode materials, an overall [18F]fluoride trapping and release efficiency of 84±5% (n=7) was achieved. X-ray photoelectron spectroscopy (XPS) was used to analyze electrode surfaces of various metal-metal systems and the findings were correlated with the performance of the electrochemical cell. To demonstrate the reactivity of the released [18F]fluoride, the cell was coupled to a flow-through reactor and automated synthesis of [18F]FDG with a repeatable decay-corrected yield of 56±4% (n=4) was completed in <15 min. A multi-human dose of 5.92 GBq [18F]FDG was also demonstrated.

We propose a discrete time discrete space Markov chain approximation with a Brownian bridge correction for computing curvilinear boundary crossing probabilities of a general diffusion process on a finite time interval. For broad classes of curvilinear boundaries and diffusion processes, we prove the convergence of the constructed approximations in the form of products of the respective substochastic matrices to the boundary crossing probabilities for the process as the time grid used to construct the Markov chains is getting finer. Numerical results indicate that the convergence rate for the proposed approximation with the Brownian bridge correction is O(n −2 ) in the case of C 2 -boundaries and a uniform time grid with n steps.

We present avidity sequencing, a sequencing chemistry that separately optimizes the processes of stepping along a DNA template and that of identifying each nucleotide within the template. Nucleotide identification uses multivalent nucleotide ligands on dye-labeled cores to form polymerase–polymer–nucleotide complexes bound to clonal copies of DNA targets. These polymer–nucleotide substrates, termed avidites, decrease the required concentration of reporting nucleotides from micromolar to nanomolar and yield negligible dissociation rates. Avidity sequencing achieves high accuracy, with 96.2% and 85.4% of base calls having an average of one error per 1,000 and 10,000 base pairs, respectively. We show that the average error rate of avidity sequencing remained stable following a long homopolymer.

We present avidity sequencing - a novel sequencing chemistry that separately optimizes the process of stepping along a DNA template and the process of identifying each nucleotide within the template. Nucleotide identification uses multivalent nucleotide ligands on dye-labeled cores to form polymerase-polymer nucleotide complexes bound to clonal copies of DNA targets. These polymer-nucleotide substrates, termed avidites, decrease the required concentration of reporting nucleotides from micromolar to nanomolar, and yield negligible dissociation rates. We demonstrate the use of avidites as a key component of a sequencing technology that surpasses Q40 accuracy and enables a diversity of applications that include single cell RNA-seq and whole human genome sequencing. We also show the advantages of this technology in sequencing through long homopolymers.

We present a novel sequencing chemistry implemented as part of the AVITI system. Relying on the proximal DNA binding sites created through DNA amplification on a solid support, avidity sequencing uses multivalent nucleotide ligands on dye-labeled cores to simultaneously form polymerase-polymer nucleotide complexes bound to clonal copies of DNA targets. These polymer-nucleotide substrates, termed avidites, decrease the required concentration of reporting nucleotides by 100x and yield a negligible dissociation rate. We demonstrate the use of avidites within a novel sequencing technology that surpasses Q40 accuracy and enables a diversity of applications that include single cell RNA-seq and whole human genome sequencing.