A method for detecting a target nucleic acid includes: (a) a step of mixing a sample containing the target nucleic acid with a nucleic acid detection solution containing i) ssDNA-protease conjugate, ii) ssDNA-zymogen conjugate, and iii) a substrate specific for the zymogen; and (b) a step of detecting a signal generated by a proximity proteolysis reaction between the ssDNA-zymogen conjugate and the ssDNA-protease conjugate which are hybridized to the target nucleic acid.

The invention generally relates to methods for quantifying an amount of enzyme molecules. Systems and methods of the invention are provided for measuring an amount of target by forming a plurality of fluid partitions, a subset of which include the target, performing an enzyme-catalyzed reaction in the subset, and detecting the number of partitions in the subset. The amount of target can be determined based on the detected number.

The invention generally relates to methods for quantifying an amount of enzyme molecules. Systems and methods of the invention are provided for measuring an amount of target by forming a plurality of fluid partitions, a subset of which include the target, performing an enzyme-catalyzed reaction in the subset, and detecting the number of partitions in the subset. The amount of target can be determined based on the detected number.

Methods and compositions for attaching cell-specific barcodes without formation of partitions is provided.

Methods and compositions for attaching cell-specific barcodes without formation of partitions is provided.

The invention generally relates to methods for quantifying an amount of enzyme molecules. Systems and methods of the invention are provided for measuring an amount of target by forming a plurality of fluid partitions, a subset of which include the target, performing an enzyme-catalyzed reaction in the subset, and detecting the number of partitions in the sunset. The amount of target can be determined based on the detected number.

The invention generally relates to methods for quantifying an amount of enzyme molecules. Systems and methods of the invention are provided for measuring an amount of target by forming a plurality of fluid partitions, a subset of which include the target, performing an enzyme-catalyzed reaction in the subset, and detecting the number of partitions in the sunset. The amount of target can be determined based on the detected number.

This disclosure provides a method of determining a sequence of nucleotides for a nucleic acid template. The method can include the steps of contacting the nucleic acid template with a conformationally labeled polymerase and at least four different nucleotide species under conditions wherein the conformationally labeled polymerase catalyzes sequential addition of the nucleotide species to form a nucleic acid complement of the nucleic acid template, wherein the sequential addition of each different nucleotide species produces a conformational signal change from the conformationally labeled polymerase and wherein the rate or time duration for the conformational signal change is distinguishable for each different nucleotide species; detecting a series of changes in the signal from the conformationally labeled polymerase under the conditions; and determining the rates or time durations for the changes in the signal, thereby determining the sequence of nucleotides for the nucleic acid template.

This disclosure provides a method of determining a sequence of nucleotides for a nucleic acid template. The method can include the steps of contacting the nucleic acid template with a conformationally labeled polymerase and at least four different nucleotide species under conditions wherein the conformationally labeled polymerase catalyzes sequential addition of the nucleotide species to form a nucleic acid complement of the nucleic acid template, wherein the sequential addition of each different nucleotide species produces a conformational signal change from the conformationally labeled polymerase and wherein the rate or time duration for the conformational signal change is distinguishable for each different nucleotide species; detecting a series of changes in the signal from the conformationally labeled polymerase under the conditions; and determining the rates or time durations for the changes in the signal, thereby determining the sequence of nucleotides for the nucleic acid template.

Methods for detecting the presence of a pathogen infection are described. In particular, this document provides a method of detecting target nucleic acids, such as pathogen-specific RNA, in a biological sample obtained from a subject, where the method comprises using one or more toehold switch sensors and an isothermal amplification step to detect the target nucleic acid. Methods specific for detecting and identify the presence of a virus such as Zika virus are also provided.