A method of manufacturing and using a nanofluidic NAND transistor sensor array scheme including a plurality of nanopore channel pillars, a plurality of respective fluidic channels, a plurality of gate electrodes, a top chamber, and a bottom chamber includes placing a sensor substrate in an electrolyte solution comprising biomolecules and DNA. The method also includes placing first and second electrodes in the electrolyte solution (Vpp and Vss of the nanofluidic NAND transistor); forming the nanopore channel pillars; placing the gate electrodes and gate insulators in respective walls of the nanopore channel pillars; applying an electrophoretic bias in the first and second electrodes; applying a bias in the gate electrodes; detecting a change in an electrode current in the electrolyte solution caused by a change in a gate voltage; and detecting a change in a surface charge in nanopore channel electrodes in the respective fluidic channels.

The present disclosure provides methods for determining the ploidy status of a chromosome in a gestating fetus from genotypic data measured from a mixed sample of DNA comprising DNA from both the mother of the fetus and from the fetus, and optionally from genotypic data from the mother and father. The ploidy state is determined by using a joint distribution model to create a plurality of expected allele distributions for different possible fetal ploidy states given the parental genotypic data, and comparing the expected allelic distributions to the pattern of measured allelic distributions measured in the mixed sample, and choosing the ploidy state whose expected allelic distribution pattern most closely matches the observed allelic distribution pattern. The mixed sample of DNA may be preferentially enriched at a plurality of polymorphic loci in a way that minimizes the allelic bias, for example using massively multiplexed targeted PCR.

The present disclosure provides methods for determining the ploidy status of a chromosome in a gestating fetus from genotypic data measured from a mixed sample of DNA comprising DNA from both the mother of the fetus and from the fetus, and optionally from genotypic data from the mother and father. The ploidy state is determined by using a joint distribution model to create a plurality of expected allele distributions for different possible fetal ploidy states given the parental genotypic data, and comparing the expected allelic distributions to the pattern of measured allelic distributions measured in the mixed sample, and choosing the ploidy state whose expected allelic distribution pattern most closely matches the observed allelic distribution pattern. The mixed sample of DNA may be preferentially enriched at a plurality of polymorphic loci in a way that minimizes the allelic bias, for example using massively multiplexed targeted PCR.

The present disclosure provides methods for determining the ploidy status of a chromosome in a gestating fetus from genotypic data measured from a mixed sample of DNA comprising DNA from both the mother of the fetus and from the fetus, and optionally from genotypic data from the mother and father. The ploidy state is determined by using a joint distribution model to create a plurality of expected allele distributions for different possible fetal ploidy states given the parental genotypic data, and comparing the expected allelic distributions to the pattern of measured allelic distributions measured in the mixed sample, and choosing the ploidy state whose expected allelic distribution pattern most closely matches the observed allelic distribution pattern. The mixed sample of DNA may be preferentially enriched at a plurality of polymorphic loci in a way that minimizes the allelic bias, for example using massively multiplexed targeted PCR.

Methods, compositions, and systems are provided for characterization of modified nucleic acids. In certain preferred embodiments, single molecule sequencing methods are provided for identification of modified nucleotides within nucleic acid sequences. Modifications detectable by the methods provided herein include chemically modified bases, enzymatically modified bases, abasic sites, non-natural bases, secondary structures, and agents bound to a template nucleic acid.

Methods, compositions, and systems are provided for characterization of modified nucleic acids. In certain preferred embodiments, single molecule sequencing methods are provided for identification of modified nucleotides within nucleic acid sequences. Modifications detectable by the methods provided herein include chemically modified bases, enzymatically modified bases, abasic sites, non-natural bases, secondary structures, and agents bound to a template nucleic acid.

The present disclosure provides methods for determining the ploidy status of a chromosome in a gestating fetus from genotypic data measured from a mixed sample of DNA comprising DNA from both the mother of the fetus and from the fetus, and optionally from genotypic data from the mother and father. The ploidy state is determined by using a joint distribution model to create a plurality of expected allele distributions for different possible fetal ploidy states given the parental genotypic data, and comparing the expected allelic distributions to the pattern of measured allelic distributions measured in the mixed sample, and choosing the ploidy state whose expected allelic distribution pattern most closely matches the observed allelic distribution pattern. The mixed sample of DNA may be preferentially enriched at a plurality of polymorphic loci in a way that minimizes the allelic bias, for example using massively multiplexed targeted PCR.

A method for sensing an analyte utilizing a sensor, the sensor including a reference electrode and a working electrode including an analyte-specific enzyme and a redox mediator, where the method includes: providing the working electrode to the analyte; accumulating charge derived from the analyte reacting with the analyte-specific enzyme and the redox mediator; measuring a potential drift of the working electrode relative to the reference electrode over a period of time, and correlating a rate of the potential drift to a concentration of the analyte.

A method including (a) providing an amplification reagent including an array of sites, and a solution having different target nucleic acids; and (b) reacting the amplification reagent to produce amplification sites each having a clonal population of amplicons from a target nucleic acid from the solution. The reacting can include simultaneously transporting the nucleic acids to the sites at an average transport rate, and amplifying the nucleic acids that transport to the sites at an average amplification rate, wherein the average amplification rate exceeds the average transport rate. The reacting can include producing a first amplicon from a nucleic acid that transports to each of the sites, and producing subsequent amplicons from the nucleic acid or from the first amplicon, wherein the average rate at which the subsequent amplicons are generated exceeds the average rate at which the first amplicon is generated.

A method including (a) providing an amplification reagent including an array of sites, and a solution having different target nucleic acids; and (b) reacting the amplification reagent to produce amplification sites each having a clonal population of amplicons from a target nucleic acid from the solution. The reacting can include simultaneously transporting the nucleic acids to the sites at an average transport rate, and amplifying the nucleic acids that transport to the sites at an average amplification rate, wherein the average amplification rate exceeds the average transport rate. The reacting can include producing a first amplicon from a nucleic acid that transports to each of the sites, and producing subsequent amplicons from the nucleic acid or from the first amplicon, wherein the average rate at which the subsequent amplicons are generated exceeds the average rate at which the first amplicon is generated.