Browsing by Author "Pinto, Alessandro"

Now showing 1 - 3 of 3
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    Continuously tunable nucleic acid hybridization probes
    (Springer Nature, 2015) Wu, Lucia R.; Wang, J. Sherry; Fang, John Z.; Reiser, Emily; Pinto, Alessandro; Pekker, Irena; Boykin, Richard; Ngouenet, Celine; Webster, Philippa J.; Beechem, Joseph; Zhang, David Yu; Bioengineering
    In silico–designed nucleic acid probes and primers often do not achieve favorable specificity and sensitivity tradeoffs on the first try, and iterative empirical sequence-based optimization is needed, particularly in multiplexed assays. We present a novel, on-the-fly method of tuning probe affinity and selectivity by adjusting the stoichiometry of auxiliary species, which allows for independent and decoupled adjustment of the hybridization yield for different probes in multiplexed assays. Using this method, we achieved near-continuous tuning of probe effective free energy. To demonstrate our approach, we enforced uniform capture efficiency of 31 DNA molecules (GC content, 0–100%), maximized the signal difference for 11 pairs of single-nucleotide variants and performed tunable hybrid capture of mRNA from total RNA. Using the Nanostring nCounter platform, we applied stoichiometric tuning to simultaneously adjust yields for a 24-plex assay, and we show multiplexed quantitation of RNA sequences and variants from formalin-fixed, paraffin-embedded samples.
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    Simultaneous and stoichiometric purification of hundreds of oligonucleotides
    (Springer Nature, 2018) Pinto, Alessandro; Chen, Sherry X.; Zhang, David Yu; Bioengineering
    Purification of oligonucleotides has traditionally relied on mobility-based separation methods. However, these are imperfect, biased, and difficult to scale high multiplex. Here, we present a method for simultaneous purification of many oligonucleotides that also normalizes concentrations. The method uses a rationally designed randomer capture probe to enrich for oligos with perfect 5' sequences, based on the observation that synthesis errors are correlated: product molecules with one or more deletions in one region are also more likely to have deletions in other regions. Next-generation sequencing analysis of 64-plex 70 nt purification products show a median 78% purity, a significant improvement over polyacrylamide gel electrophoresis and high pressure liquid chromatography (60% median purity). Additionally, 89% of the oligo products are within a factor of 2 of the median concentration.
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    Stoichiometric nucleic acid purification using randomer capture probe libraries
    (2022-08-16) Zhang, David; Pinto, Alessandro; Rice University; William Marsh Rice University; United States Patent and Trademark Office
    This disclosure describes a method of purifying several full-length oligonucleotide targets from corresponding synthesis truncation products, in a way that ensures roughly stoichiometric equality among the targets.