Compositions, kits, and methods for performing rapid polymerase chain reaction (PCR) to amplify a target nucleic acid in a biological sample are disclosed. The methods include the use of at least one hybridization stabilizer and/or the adjustment of the thermocycling profiles between initiation and propagation phases of the amplification process. Also disclosed are methods of detecting the target nucleic acid following amplification thereof, as well as reaction mixtures that may be utilized in said methods.

Compositions, kits, and methods for performing rapid polymerase chain reaction (PCR) to amplify a target nucleic acid in a biological sample are disclosed. The methods include the use of at least one hybridization stabilizer and/or the adjustment of the thermocycling profiles between initiation and propagation phases of the amplification process. Also disclosed are methods of detecting the target nucleic acid following amplification thereof, as well as reaction mixtures that may be utilized in said methods.

A nucleic acid amplification method includes a step of heating a first region of a container housing a droplet containing a target nucleic acid and a sample necessary for amplification of the target nucleic acid to a denaturation temperature of the target nucleic acid and heating a second region different from the first region to a synthesis temperature of the target nucleic acid, and an amplification step of repeating a cycle through a denaturation stage at which the droplet housed in the container is moved to and retained in the first region and a synthesis stage at which the droplet is moved to and retained in the second region at a plurality of times. At the amplification step, periods of part of cycles of the plurality of cycles are made shorter than periods of the other cycles.

A nucleic acid amplification method includes a step of heating a first region of a container housing a droplet containing a target nucleic acid and a sample necessary for amplification of the target nucleic acid to a denaturation temperature of the target nucleic acid and heating a second region different from the first region to a synthesis temperature of the target nucleic acid, and an amplification step of repeating a cycle through a denaturation stage at which the droplet housed in the container is moved to and retained in the first region and a synthesis stage at which the droplet is moved to and retained in the second region at a plurality of times. At the amplification step, periods of part of cycles of the plurality of cycles are made shorter than periods of the other cycles.

The present invention provides methods and systems for sequencing long nucleic acid fragment. The present invention also provides a method of sequencing a target polynucleotide with fewer probes. Further, the present invention provides a method of sequencing a target polynucleotide with longer reads. Locus-specific, ligation-assisted sequencing/genotyping method and ligation-captured sequencing method are also provided in the present invention. The methods of the present invention allow low-cost, high-throughput and accurate sequencing of nucleic acids.

The present invention belongs to the field of diagnosis of disease. Thus the present invention is focused on a method and kit and system for quantifying the level of minimal residual disease (MRD) in a subject who has been treated for said disease, as well as a method of treatment of said disease in a subject which comprises a step of quantifying the level of minimal residual diseases, wherein said quantifying comprises: (a) identifying, amplifying and sequencing a nucleotide sequence in a biological sample obtained from said subject after treatment for said disease, wherein the gDNA of said biological sample has an average weight, k, per cell, and wherein said nucleotide sequence is identified using primers and is amplified using an amount, D, to afford a first list of characters; (b) identifying, amplifying and sequencing a nucleotide sequence in a biological sample obtained from a subject with said disease using the same primers as in step (a) to afford a second list of characters; (c) determining, for each first list of characters obtained in step (a), the degree of similarity, DS, with each second list of characters obtained in step (b); (d) selecting, for each first list of characters obtained in step (a), the DS of highest value, DS.sub.HV; (e) adding up the number of first lists of characters obtained in step (a) which have a DS.sub.HV that is greater than a threshold value, T, to obtain L.sub.c; (f) adding up the total number of lists of characters, L.sub.t, in the first list of characters; and (g) calculating the level of minimal residual disease (MRD) according to either of the following formulae:
MRD=(L.sub.c×k)/(L.sub.t×D)
or
MRD=L.sub.c/L.sub.t
or
MRD=L.sub.c×(D/k)/L.sub.t.sup.2.

The present invention belongs to the field of diagnosis of disease. Thus the present invention is focused on a method and kit and system for quantifying the level of minimal residual disease (MRD) in a subject who has been treated for said disease, as well as a method of treatment of said disease in a subject which comprises a step of quantifying the level of minimal residual diseases, wherein said quantifying comprises: (a) identifying, amplifying and sequencing a nucleotide sequence in a biological sample obtained from said subject after treatment for said disease, wherein the gDNA of said biological sample has an average weight, k, per cell, and wherein said nucleotide sequence is identified using primers and is amplified using an amount, D, to afford a first list of characters; (b) identifying, amplifying and sequencing a nucleotide sequence in a biological sample obtained from a subject with said disease using the same primers as in step (a) to afford a second list of characters; (c) determining, for each first list of characters obtained in step (a), the degree of similarity, DS, with each second list of characters obtained in step (b); (d) selecting, for each first list of characters obtained in step (a), the DS of highest value, DS.sub.HV; (e) adding up the number of first lists of characters obtained in step (a) which have a DS.sub.HV that is greater than a threshold value, T, to obtain L.sub.c; (f) adding up the total number of lists of characters, L.sub.t, in the first list of characters; and (g) calculating the level of minimal residual disease (MRD) according to either of the following formulae:
MRD=(L.sub.c×k)/(L.sub.t×D)
or
MRD=L.sub.c/L.sub.t
or
MRD=L.sub.c×(D/k)/L.sub.t.sup.2.

The present invention is focused on a method, kit and system for determining the presence or absence of minimal residual disease in a subject who has been treated for a proliferative disease wherein said method, kit and system comprise: (A) amplifying and sequencing at least one nucleotide sequence comprised in genomic DNA from a biological sample obtained from said subject prior to treatment for said disease, to obtain a first list of characters reading from left to right; (B) amplifying and sequencing at least one nucleotide sequence comprised in genomic DNA from a biological sample obtained from said subject after treatment for said disease, to obtain a second list of characters reading from left to right,
wherein when a nucleotide sequence is mutated it is a genetic marker for said proliferative disease; (C) determining, for each second list of characters obtained in step (B), the degree of similarity, DS, with each first list of characters obtained in step (A); (D) selecting, for each second list of characters obtained in step (B), the DS of highest value, DS.sub.HV; (E) adding up the number of second lists of characters which have a DS.sub.HV that is greater than a threshold value, T, to obtain L.sub.c, (F) adding up the total number of second lists of characters, L.sub.t; (G) calculating the level of minimal residual disease, MRD, according to any of the following formulae:

MRD=(L.sub.c×k)/(L.sub.t×D)

or

MRD=L.sub.c/L.sub.t

or

MRD=g×L.sub.c×(D/k)/L.sub.t.sup.2; (H) determining (i) the minimum variant read frequency, min VRF, of said genetic marker, (ii) the limit of detection, D-limit, of said genetic marker (iii) the average mutation noise, avMut and (iv) the average position noise, avPos; (I) determining the experimental sensitivity, ES, from the greater of the min VRF, D-limit, avMut and avPos or from the greater of min VRF and D-limit; (J) determining the presence or absence of minimal residual disease in said subject

The present invention is focused on a method, kit and system for determining the presence or absence of minimal residual disease in a subject who has been treated for a proliferative disease wherein said method, kit and system comprise: (A) amplifying and sequencing at least one nucleotide sequence comprised in genomic DNA from a biological sample obtained from said subject prior to treatment for said disease, to obtain a first list of characters reading from left to right; (B) amplifying and sequencing at least one nucleotide sequence comprised in genomic DNA from a biological sample obtained from said subject after treatment for said disease, to obtain a second list of characters reading from left to right,
wherein when a nucleotide sequence is mutated it is a genetic marker for said proliferative disease; (C) determining, for each second list of characters obtained in step (B), the degree of similarity, DS, with each first list of characters obtained in step (A); (D) selecting, for each second list of characters obtained in step (B), the DS of highest value, DS.sub.HV; (E) adding up the number of second lists of characters which have a DS.sub.HV that is greater than a threshold value, T, to obtain L.sub.c, (F) adding up the total number of second lists of characters, L.sub.t; (G) calculating the level of minimal residual disease, MRD, according to any of the following formulae:

MRD=(L.sub.c×k)/(L.sub.t×D)

or

MRD=L.sub.c/L.sub.t

or

MRD=g×L.sub.c×(D/k)/L.sub.t.sup.2; (H) determining (i) the minimum variant read frequency, min VRF, of said genetic marker, (ii) the limit of detection, D-limit, of said genetic marker (iii) the average mutation noise, avMut and (iv) the average position noise, avPos; (I) determining the experimental sensitivity, ES, from the greater of the min VRF, D-limit, avMut and avPos or from the greater of min VRF and D-limit; (J) determining the presence or absence of minimal residual disease in said subject

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.