The present invention provides methods, compositions and kits for assembling an enzyme-deoxyribonucleic acid (DNA) complex for use in preparing a double stranded DNA molecule comprising one or more loci of interest for determining the methylation status of the one or more loci of interest therein.

Methods of detecting methylated CpG are provided. Accordingly, there is provided a method of determining CpG methylation status in a DNA sample, the method comprising: (a) subjecting the DNA sample to bisulfite conversion; (b) amplifying said DNA sample following said (a) to obtain an amplified DNA sample; (c) labeling CpG sites in said amplified DNA sample with a label to obtain a labeled DNA sample; (d) contacting said labeled DNA sample on an array comprising a plurality of probes for said DNA under conditions which allow specific hybridization between said plurality of probes and said DNA; and (e)detecting said hybridization, wherein an amount of said label is indicative of the CpG methylation status in said DNA sample.

Methods of detecting methylated CpG are provided. Accordingly, there is provided a method of determining CpG methylation status in a DNA sample, the method comprising: (a) subjecting the DNA sample to bisulfite conversion; (b) amplifying said DNA sample following said (a) to obtain an amplified DNA sample; (c) labeling CpG sites in said amplified DNA sample with a label to obtain a labeled DNA sample; (d) contacting said labeled DNA sample on an array comprising a plurality of probes for said DNA under conditions which allow specific hybridization between said plurality of probes and said DNA; and (e)detecting said hybridization, wherein an amount of said label is indicative of the CpG methylation status in said DNA sample.

Provided herein are methods, compositions and kits for the generation of bisulfite-converted next generation sequencing (NGS) libraries. The methods, compositions and kits provided herein can be useful, for example, for the production of libraries from genomic DNA that allow for determination of the methylation status across the genome, i.e. the methylome. The methods, compositions and kits provided herein can also be utilized to query methylation status at a particular genomic locus or loci. Moreover, the methods provided herein can be employed for high-throughput sequencing of bisulfite-converted DNA while maintaining the directional (strandedness) information of the original nucleic acid sample.

Provided herein are methods, compositions and kits for the generation of bisulfite-converted next generation sequencing (NGS) libraries. The methods, compositions and kits provided herein can be useful, for example, for the production of libraries from genomic DNA that allow for determination of the methylation status across the genome, i.e. the methylome. The methods, compositions and kits provided herein can also be utilized to query methylation status at a particular genomic locus or loci. Moreover, the methods provided herein can be employed for high-throughput sequencing of bisulfite-converted DNA while maintaining the directional (strandedness) information of the original nucleic acid sample.

The invention provides systems and methods for determining patterns of modification to a genome of a subject by representing the genome using a graph, such as a directed acyclic graph (DAG) with divergent paths for regions that are potentially subject to modification, profiling segments of the genome for evidence of epigenetic modification, and aligning the profiled segments to the DAG to determine locations and patterns of the epigenetic modification within the genome.

The invention provides systems and methods for determining patterns of modification to a genome of a subject by representing the genome using a graph, such as a directed acyclic graph (DAG) with divergent paths for regions that are potentially subject to modification, profiling segments of the genome for evidence of epigenetic modification, and aligning the profiled segments to the DAG to determine locations and patterns of the epigenetic modification within the genome.

In an aspect, there is provided a method of detecting the presence of ctDNA from cancer cells in a subject comprising: (a) providing a sample of cell-free DNA from a subject; (b) subjecting the sample to library preparation to permit subsequent sequencing of the cell-free methylated DNA; (c) optionally adding a first amount of filler DNA to the sample, wherein at least a portion of the filler DNA is methylated, then further optionally denaturing the sample; (d) capturing cell-free methylated DNA using a binder selective for methylated polynucleotides; (e) sequencing the captured cell-free methylated DNA; (f) comparing the sequences of the captured cell-free methylated DNA to control cell-free methylated DNAs sequences from healthy and cancerous individuals; (g) identifying the presence of DNA from cancer cells if there is a statistically significant similarity between one or more sequences of the captured cell-free methylated DNA and cell-free methylated DNAs sequences from cancerous individuals; wherein in at least one of the capturing step, the comparing step or the identifying step, the subject cell-free methylated DNA is limited to a sub-population according to a fragment length metric.

In an aspect, there is provided a method of detecting the presence of ctDNA from cancer cells in a subject comprising: (a) providing a sample of cell-free DNA from a subject; (b) subjecting the sample to library preparation to permit subsequent sequencing of the cell-free methylated DNA; (c) optionally adding a first amount of filler DNA to the sample, wherein at least a portion of the filler DNA is methylated, then further optionally denaturing the sample; (d) capturing cell-free methylated DNA using a binder selective for methylated polynucleotides; (e) sequencing the captured cell-free methylated DNA; (f) comparing the sequences of the captured cell-free methylated DNA to control cell-free methylated DNAs sequences from healthy and cancerous individuals; (g) identifying the presence of DNA from cancer cells if there is a statistically significant similarity between one or more sequences of the captured cell-free methylated DNA and cell-free methylated DNAs sequences from cancerous individuals; wherein in at least one of the capturing step, the comparing step or the identifying step, the subject cell-free methylated DNA is limited to a sub-population according to a fragment length metric.

Provided are methods for preparing samples for sequencing. Also provided are methods for sequence analysis. Also provided are methods for classifying multiple aspects of a nucleotide repeat expansion disorder in a single sequencing assay. Also provided are methods for genotyping a target nucleic acid sequence.