An example method includes reacting a first solution and a different, second solution on a flow cell by flowing the first solution over amplification sites on the flow cell and subsequently flowing the second solution over the amplification sites. The first solution includes target nucleic acids and a first reagent mixture that comprises nucleoside triphosphates and replication enzymes. The target nucleic acids in the first solution transport to and bind to the amplification sites at a transport rate. The first reagent mixture amplifies the target nucleic acids that are bound to the amplification sites to produce clonal populations of amplicons originating from corresponding target nucleic acids. The amplicons are produced at an amplification rate that exceeds the transport rate. The second solution includes a second reagent mixture and lacks the target nucleic acids. The second solution is to increase a number of the amplicons at the amplification sites.

An example method includes reacting a first solution and a different, second solution on a flow cell by flowing the first solution over amplification sites on the flow cell and subsequently flowing the second solution over the amplification sites. The first solution includes target nucleic acids and a first reagent mixture that comprises nucleoside triphosphates and replication enzymes. The target nucleic acids in the first solution transport to and bind to the amplification sites at a transport rate. The first reagent mixture amplifies the target nucleic acids that are bound to the amplification sites to produce clonal populations of amplicons originating from corresponding target nucleic acids. The amplicons are produced at an amplification rate that exceeds the transport rate. The second solution includes a second reagent mixture and lacks the target nucleic acids. The second solution is to increase a number of the amplicons at the amplification sites.

A method for seeding and amplifying target nucleic acids derived from a sample in a cluster at a site on a surface of a substrate includes retaining at least a portion of the target nucleic acids in an inactive form that cannot seed to provide a relatively low concentration of active form target nucleic acids available for seeding. As the active form target nucleic acids seed on the surface of the substrate, they may be amplified. Because the concentration of active form target nucleic acids is low, the likelihood is low that a second active form target nucleic acid will seed at the same site within the same cluster before the first active form target nucleic acid is sufficiently amplified to dominate. Accordingly, the likelihood that the cluster will pass filters is increased relative to traditional seeding and amplification methods employing a higher concentration of active form target nucleic acids.

A method for seeding and amplifying target nucleic acids derived from a sample in a cluster at a site on a surface of a substrate includes retaining at least a portion of the target nucleic acids in an inactive form that cannot seed to provide a relatively low concentration of active form target nucleic acids available for seeding. As the active form target nucleic acids seed on the surface of the substrate, they may be amplified. Because the concentration of active form target nucleic acids is low, the likelihood is low that a second active form target nucleic acid will seed at the same site within the same cluster before the first active form target nucleic acid is sufficiently amplified to dominate. Accordingly, the likelihood that the cluster will pass filters is increased relative to traditional seeding and amplification methods employing a higher concentration of active form target nucleic acids.

Provided is a surface probe-based quantitative PCR testing system, comprising: (a) a solid phase carrier; (b) a specific primer pair of a sequence to be tested, which comprises a first primer and a second primer; and (c) a quenching probe. Further provided are a method for quantitative PCR testing and a kit.

Provided is a surface probe-based quantitative PCR testing system, comprising: (a) a solid phase carrier; (b) a specific primer pair of a sequence to be tested, which comprises a first primer and a second primer; and (c) a quenching probe. Further provided are a method for quantitative PCR testing and a kit.

A method for identifying a nucleotide in a primed template nucleic acid, including the steps of (a) providing a vessel having a primed template nucleic acid, polymerase and a nucleotide cognate of a first base type; (b) examining the vessel for a stabilized ternary complex including the polymerase and the nucleotide cognate of the first base type bound at a base position of the primed template nucleic acid; (c) delivering a nucleotide cognate of a second base type to the vessel, whereby the vessel retains the primed template nucleic acid and the polymerase from step (b); (d) examining the vessel for a stabilized ternary complex including the polymerase and the nucleotide cognate of the second base type bound at the base position of the primed template nucleic acid; and (e) identifying the type of nucleotide at the base position of the primed template nucleic acid.

A method for identifying a nucleotide in a primed template nucleic acid, including the steps of (a) providing a vessel having a primed template nucleic acid, polymerase and a nucleotide cognate of a first base type; (b) examining the vessel for a stabilized ternary complex including the polymerase and the nucleotide cognate of the first base type bound at a base position of the primed template nucleic acid; (c) delivering a nucleotide cognate of a second base type to the vessel, whereby the vessel retains the primed template nucleic acid and the polymerase from step (b); (d) examining the vessel for a stabilized ternary complex including the polymerase and the nucleotide cognate of the second base type bound at the base position of the primed template nucleic acid; and (e) identifying the type of nucleotide at the base position of the primed template nucleic acid.

Provided are compositions and processes that utilize genomic regions that are differentially methylated between a mother and her fetus to separate, isolate or enrich fetal nucleic acid from a maternal sample. The compositions and processes described herein are particularly useful for non-invasive prenatal diagnostics, including the detection of chromosomal aneuploidies.

Provided are compositions and processes that utilize genomic regions that are differentially methylated between a mother and her fetus to separate, isolate or enrich fetal nucleic acid from a maternal sample. The compositions and processes described herein are particularly useful for non-invasive prenatal diagnostics, including the detection of chromosomal aneuploidies.