This invention relates to a method that covalently modifies unmodified and hydroxymethylated genomic sites in fetal specific genetic material present in maternal blood DNA samples and produce the adjacent genomic regions for detecting fetal aneuploidies and fetal gender using quantitative real time PCR or sequencing. A large panel of differently labeled sites and regions between maternal and fetal genetic material has been identified and they validity for diagnostic purposes of fetal trisomy of chromosome 21 has been demonstrated.

This invention relates to a method that covalently modifies unmodified and hydroxymethylated genomic sites in fetal specific genetic material present in maternal blood DNA samples and produce the adjacent genomic regions for detecting fetal aneuploidies and fetal gender using quantitative real time PCR or sequencing. A large panel of differently labeled sites and regions between maternal and fetal genetic material has been identified and they validity for diagnostic purposes of fetal trisomy of chromosome 21 has been demonstrated.

Methods, compositions, kits, and systems are provided for identifying regions of genomic DNA bound to a protein. The methods may include contacting genomic DNA with an adenine methyltransferase (A-MTase), where the A-MTase causes methylation of adenine residues in regions of the genomic DNA not bound to a protein; and conducting single molecule long read sequencing of the contacted genomic DNA to detect locations in the genomic DNA lacking methylated adenine residues to identify regions of genomic DNA bound to a protein. The bound regions may be nucleosome positions and the methods may determinenucleosome positions in genomic DNA. Also provided are methods for visualization of regions of chromatin not bound to a protein and spatially available as a substrate for an adenine methyltransferase (A-MTase) in a cell by visualizing location of methylated adenines after contacting the cells with the A-MTase.

Methods, compositions, kits, and systems are provided for identifying regions of genomic DNA bound to a protein. The methods may include contacting genomic DNA with an adenine methyltransferase (A-MTase), where the A-MTase causes methylation of adenine residues in regions of the genomic DNA not bound to a protein; and conducting single molecule long read sequencing of the contacted genomic DNA to detect locations in the genomic DNA lacking methylated adenine residues to identify regions of genomic DNA bound to a protein. The bound regions may be nucleosome positions and the methods may determinenucleosome positions in genomic DNA. Also provided are methods for visualization of regions of chromatin not bound to a protein and spatially available as a substrate for an adenine methyltransferase (A-MTase) in a cell by visualizing location of methylated adenines after contacting the cells with the A-MTase.

Provided herein are methods, systems, and compositions for determining a base in a polynucleotide. In various aspects, the methods, systems, and compositions presented herein are useful for performing 4-base, 5-base, or 6-base sequencing of polynucleotide molecules, for example, from liquid biopsy samples or wherein the base is a low frequency mutation.

Provided herein are methods, systems, and compositions for determining a base in a polynucleotide. In various aspects, the methods, systems, and compositions presented herein are useful for performing 4-base, 5-base, or 6-base sequencing of polynucleotide molecules, for example, from liquid biopsy samples or wherein the base is a low frequency mutation.

Examples provided herein are related to detecting methylcytosine and its derivatives using S-adenosyl-L-methionine analogs (xSAMs). Compositions and methods for performing such detection are disclosed. A target polynucleotide may include cytosine (C) and methylcytosine (mC). The method may include (a) protecting the C in the target polynucleotide from deamination; and (b) after step (a), deaminating the mC in the target polynucleotide to form thymine (T). Protecting the C from deamination may include adding a protective group to the 5 position of the C, e.g., using a methyltransferase enzyme that adds the first protective group from an xSAM.

Examples provided herein are related to detecting methylcytosine and its derivatives using S-adenosyl-L-methionine analogs (xSAMs). Compositions and methods for performing such detection are disclosed. A target polynucleotide may include cytosine (C) and methylcytosine (mC). The method may include (a) protecting the C in the target polynucleotide from deamination; and (b) after step (a), deaminating the mC in the target polynucleotide to form thymine (T). Protecting the C from deamination may include adding a protective group to the 5 position of the C, e.g., using a methyltransferase enzyme that adds the first protective group from an xSAM.

Provided herein are methods, systems, and compositions for determining a base in a polynucleotide. In various aspects, the methods, systems, and compositions presented herein are useful for performing 4-base, 5-base, or 6-base sequencing of polynucleotide molecules, for example, from liquid biopsy samples or wherein the base is a low frequency mutation.

Provided herein are methods, systems, and compositions for determining a base in a polynucleotide. In various aspects, the methods, systems, and compositions presented herein are useful for performing 4-base, 5-base, or 6-base sequencing of polynucleotide molecules, for example, from liquid biopsy samples or wherein the base is a low frequency mutation.