Digital Analysis of Molecular Analytes Using Electrical Methods

Abstract

Electrical detection methods are used to identify and further characterize single-molecule target analytes such as proteins and nucleic acids. A composition including a probe region and a tail region is contacted with a target analyte. The probe region specifically binds to the target analyte. The tail region is coupled to the probe region, and includes a nucleic acid template for polynucleotide synthesis. When conditions are such that polynucleotide synthesis occurs along the tail region, one hydrogen ion is released for every nucleotide that is incorporated into the tail region. A transistor such as an ISFET detects and measures changes in ion concentration, and these measurements can be used to identify the tail region and thus characterize the corresponding target analyte.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS[0001]This application claims priority to U.S. Provisional Application No. 61 / 868,988, filed on Aug. 22, 2013, which is incorporated by reference herein in its entirety. This application also incorporates by reference in their entirety U.S. Provisional Application No. 61 / 728,067 and International Pat. Application No. PCT / US2013 / 070797.BACKGROUND[0002]1. Technical Field[0003]This disclosure relates compositions and methods useful for the electrical detection of molecules, and more specifically, to the use of digitized electrical signals and the use of error correction protocols to characterize complex mixtures of target analytes.[0004]2. Description of the Related Art[0005]Multiple molecular and biochemical approaches are available for molecular analyte identification and quantification. Examples include commonly used nucleic acid-based assays such as qPCR (quantitative polymerase chain reaction) and DNA microarray, and protein-based approaches ...

AI Technical Summary

Benefits of technology

The invention provides a composition that includes a probe region that specifically binds to a target analyte, a tail region that comprises a homopolymeric base region, and a linker region that connects the probe region and the tail region. The linker region can specifically bind to a portion of the tail region. The composition can be used to characterize the target analyte by contacting it with the probe region and detecting the output signals from the spatially separate regions of a substrate. The invention also provides methods for detecting the target analyte using the composition. The technical effect of the invention is to provide a more efficient and accurate method for identifying and characterizing target analytes.

Problems solved by technology

However, various limitations exist in current analyte analysis technologies.

For example, current methods have limitations of sensitivity, especially where analytes are present in biological samples at low copy numbers or in low concentrations.

However, amplification techniques introduce biases and inaccuracies into the quantification.

Moreover, amplification is not possible for protein and peptides.

Due to lack of sensitivity, approaches for detection and quantification often require relatively large sample volumes.

Current methods are also limited in their capacity for identification and quantification of a large number of analytes.

In addition, current technologies lack of capability to detect and quantify nucleic acids and proteins simultaneously.

Current methods often generate errors during analyte detection and quantification due to conditions such as weak signal detection, false positives, and other mistakes.

These errors may result in the misidentification and inaccurate quantification of analytes.

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