Methods and systems for decreasing amplification bias and primer-dimer formation in amplification reactions and for amplifying a plurality of target polynucleotides from a sample in a single reaction and for sequencing the target polynucleotides where samples can include forensic samples and where target polynucleotides can include identity- or ancestry-informative markers, short tandem repeats (STRs) and single nucleotide polymorphisms (SNPs). Methods of determining a nucleotide spacer sequence for disrupting primer dimer formation can include: receiving a set of primer sequences; determining a plurality of candidate spacers between an adapter sequence and a gene-specific portion of the primer sequence, the determined plurality of candidate spacers comprises sequences that disrupt stable interactions between sequences of the set of primer sequences; ranking candidate spacers that meet a predetermined threshold value of stable interactions in the extension sequences; and outputting a set of the ranked spacers that meet the predetermined threshold.

Methods and systems for decreasing amplification bias and primer-dimer formation in amplification reactions and for amplifying a plurality of target polynucleotides from a sample in a single reaction and for sequencing the target polynucleotides where samples can include forensic samples and where target polynucleotides can include identity- or ancestry-informative markers, short tandem repeats (STRs) and single nucleotide polymorphisms (SNPs). Methods of determining a nucleotide spacer sequence for disrupting primer dimer formation can include: receiving a set of primer sequences; determining a plurality of candidate spacers between an adapter sequence and a gene-specific portion of the primer sequence, the determined plurality of candidate spacers comprises sequences that disrupt stable interactions between sequences of the set of primer sequences; ranking candidate spacers that meet a predetermined threshold value of stable interactions in the extension sequences; and outputting a set of the ranked spacers that meet the predetermined threshold.

Methods and reagents for preparing nucleic acid samples for sequencing are provided. The samples include formalin-fixed paraffin-embedded (FFPE) samples. The methods comprise contacting a nucleic acid sample with a multimeric barcoding reagent comprising barcode regions linked together and appending barcode sequences to nucleic acid sequences of a target nucleic acid molecule. Methods are also provided that additionally use in-vitro transposition, coupling sequences and/or primer-extension to append barcode sequences to nucleic acid sequences of a target nucleic acid molecule.

A method for specifically and efficiently quantifying the expression of targeted RNA variants with specific terminal sequences suitable to identify multiple isoforms bearing complex heterogeneity in terminal sequences by hybridizing a 5′-Dbs-adapter to the 5′-end of target RNAs, wherein the 5′-Dbs-adapter has a stem-loop structure whose protruding 5′-end base-pairs with the 5′-end of target RNAs, and wherein the loop region of 5′-Dbs-adapter contains a base-lacking spacer which will terminate reverse transcription in a subsequent step; hybridizing a 3′db-adapter to the 3′-end of target RNAs, wherein the 3′-db-adapter has a stem-loop structure whose protruding 3′-end base-pairs with the 3′-end of target RNAs; ligating both adapters with target RNAs by RN12 ligation to form a “dumbbell-like” structure; and, amplifying and quantifying the ligation product by RT-PCR.

A method for specifically and efficiently quantifying the expression of targeted RNA variants with specific terminal sequences suitable to identify multiple isoforms bearing complex heterogeneity in terminal sequences by hybridizing a 5′-Dbs-adapter to the 5′-end of target RNAs, wherein the 5′-Dbs-adapter has a stem-loop structure whose protruding 5′-end base-pairs with the 5′-end of target RNAs, and wherein the loop region of 5′-Dbs-adapter contains a base-lacking spacer which will terminate reverse transcription in a subsequent step; hybridizing a 3′db-adapter to the 3′-end of target RNAs, wherein the 3′-db-adapter has a stem-loop structure whose protruding 3′-end base-pairs with the 3′-end of target RNAs; ligating both adapters with target RNAs by RN12 ligation to form a “dumbbell-like” structure; and, amplifying and quantifying the ligation product by RT-PCR.

A biomolecule is more easily and reliably reciprocated in a nanopore. An adapter molecule that directly or indirectly binds to a biomolecule to be analyzed comprises a three-dimensional structure formation domain consisting of a single-stranded nucleotide.

A biomolecule is more easily and reliably reciprocated in a nanopore. An adapter molecule that directly or indirectly binds to a biomolecule to be analyzed comprises a three-dimensional structure formation domain consisting of a single-stranded nucleotide.

The present disclosure relates to methods for enriching circulating tumor DNA (ctDNA) to enhance early disease detection or predictions of disease progression. The present disclosure also relates to methods for enriching circulating fetal cell free DNA (fetal cfDNA) to enhance early disease detection. In some embodiments, the method comprises enriching ctDNA or fetal cfDNA in a sample by selecting for cell-free nucleic acid fragments that are less than 150 bp prior to copy number alteration (CNA) analysis. Also disclosed are compositions, systems, and computer-program products for analyzing circulating cell free nucleic acids by any of the methods disclosed herein.

The present disclosure relates to methods for enriching circulating tumor DNA (ctDNA) to enhance early disease detection or predictions of disease progression. The present disclosure also relates to methods for enriching circulating fetal cell free DNA (fetal cfDNA) to enhance early disease detection. In some embodiments, the method comprises enriching ctDNA or fetal cfDNA in a sample by selecting for cell-free nucleic acid fragments that are less than 150 bp prior to copy number alteration (CNA) analysis. Also disclosed are compositions, systems, and computer-program products for analyzing circulating cell free nucleic acids by any of the methods disclosed herein.

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.