Provided herein is a reverse transcriptase mixture comprising a reverse transcriptase and a colored dye at a concentration in the range of 0.003%-1% (v/w). The colored dye may be visually observed during transfer of the mix from one vessel to another and addition of the mix to another mix can be confirmed by eye by observing the colored dye.

Methods and systems for highly sensitive detection of methylation changes in DNA samples are provided, particularly in DNA samples obtained from biological fluids such as plasma and urine.

Methods and systems for highly sensitive detection of methylation changes in DNA samples are provided, particularly in DNA samples obtained from biological fluids such as plasma and urine.

The present methods are exemplified by a process in which maternal blood containing fetal DNA is diluted to a nominal value of approximately 0.5 genome equivalent of DNA per reaction sample. Digital analysis is then be used to detect aneuploidy, such as the trisomy that causes Down Syndrome. Since aneuploidies do not present a mutational change in sequence, and are merely a change in the number of chromosomes, it has not been possible to detect them in a fetus without resorting to invasive techniques such as amniocentesis or chorionic villi sampling. Digital amplification allows the detection of aneuploidy using massively parallel amplification and detection methods, examining, e.g., 10,000 genome equivalents.

The present methods are exemplified by a process in which maternal blood containing fetal DNA is diluted to a nominal value of approximately 0.5 genome equivalent of DNA per reaction sample. Digital analysis is then be used to detect aneuploidy, such as the trisomy that causes Down Syndrome. Since aneuploidies do not present a mutational change in sequence, and are merely a change in the number of chromosomes, it has not been possible to detect them in a fetus without resorting to invasive techniques such as amniocentesis or chorionic villi sampling. Digital amplification allows the detection of aneuploidy using massively parallel amplification and detection methods, examining, e.g., 10,000 genome equivalents.

Phosphoramidate-based monomers are provided for use in the synthesis of expandable polymers for nanopore-based sensing. Such monomers comprising a reporter construct that contain a first reporter code, a symmetrical chemical brancher bearing a translocation control element, and a second reporter code, wherein the ends of the reporter construct are attached to phosphoramidate-nucleoside. Related methods and products are also provided.

Phosphoramidate-based monomers are provided for use in the synthesis of expandable polymers for nanopore-based sensing. Such monomers comprising a reporter construct that contain a first reporter code, a symmetrical chemical brancher bearing a translocation control element, and a second reporter code, wherein the ends of the reporter construct are attached to phosphoramidate-nucleoside. Related methods and products are also provided.

Provided herein are methods for de-crosslinking fixed biological samples (e.g., fixed biological samples including aminal crosslinks). The compositions and methods disclosed can de-crosslink oligonucleotides (e.g., DNA or RNA) or proteins from fixed biological samples (e.g., fixed biological samples with aminal crosslinks), wherein the de-crosslinked biological sample is compatible with and can be used in spatial gene expression analysis.

Provided herein are methods for de-crosslinking fixed biological samples (e.g., fixed biological samples including aminal crosslinks). The compositions and methods disclosed can de-crosslink oligonucleotides (e.g., DNA or RNA) or proteins from fixed biological samples (e.g., fixed biological samples with aminal crosslinks), wherein the de-crosslinked biological sample is compatible with and can be used in spatial gene expression analysis.

The present invention relates to the field of viral nucleic acid detection. In particular, the present invention provides a pretreatment method for viral nucleic acid detection. The method includes mixing a pretreatment solution containing a sample with a nucleic acid releasing agent and a qPCR amplification reagent, wherein the pretreatment solution includes Tris-HCl, EDTA-2Na, sodium chloride, a ribonuclease (RNase) inhibitor, and an antibiotic; and the pretreatment solution has a pH of 6.5-8.0.