Aspects of the present disclosure include compositions that make use of phosphorus and/or nucleobase protecting groups which find use in the synthesis of long polynucleotides. Phosphorus protecting groups are provided that help increase the stepwise coupling yield and/or phosphorous protecting groups that can be removed during the oxidation step. Amidine nucleobase protecting groups are provided that find use in the subject compositions and methods which provides for e.g., increased resistance to depurination during polynucleotide synthesis. In some instances, the methods and compositions disclosed herein utilize a combination of the phosphorus and amidine nucleobase protecting groups in the synthesis of polynucleotides having a sequence of 200 or more monomeric units in length. Also provided are methods for synthesizing a polynucleotide (e.g., a DNA) using one or more compounds disclosed herein.

The present invention provides an aptamer that specifically hinds CD44, composition comprising the aptamer, as well as methods for detecting CD44 and for targeted delivery to CD44-expressing cells.

Provided herein are methods of preparing cell-free DNA (cfDNA) for sequencing such that variant allele frequencies are maintained. Also provided are sequencing libraries prepared according to such methods. In addition, methods are provided for analyzing sequencing reads to determine variant allele frequencies. These methods may be used for diagnosing and/or evaluating cancer patients.

Provided herein are methods of preparing cell-free DNA (cfDNA) for sequencing such that variant allele frequencies are maintained. Also provided are sequencing libraries prepared according to such methods. In addition, methods are provided for analyzing sequencing reads to determine variant allele frequencies. These methods may be used for diagnosing and/or evaluating cancer patients.

A nano-structured ceramic film with controlled pore size for the high throughput synthesis of oligonucleotides (DNA and RNA). The film can be cut into chips of predetermined size, and code printed for optical recognition in automated DNA synthesizers. The chips are easily activated under very mild conditions and silanization proceeds uniformly to allow reagents to flow unhindered through its open pores. Mono layer modifications, such as covalently bound silane coupling agents, allows for the addition of universal linkers and improved yields compared to conventional approaches.

A nano-structured ceramic film with controlled pore size for the high throughput synthesis of oligonucleotides (DNA and RNA). The film can be cut into chips of predetermined size, and code printed for optical recognition in automated DNA synthesizers. The chips are easily activated under very mild conditions and silanization proceeds uniformly to allow reagents to flow unhindered through its open pores. Mono layer modifications, such as covalently bound silane coupling agents, allows for the addition of universal linkers and improved yields compared to conventional approaches.

Provided herein are compositions, methods and systems relating to libraries of polynucleotides such that the libraries allow for accurate and efficient hybridization after binding to target sequences. Further provided herein are probes, blockers, additives, buffers, and methods that result in improved hybridization. Such compositions and methods are useful for improvement of Next Generation Sequencing applications, such as reducing off-target binding or reducing workflow times.

The present disclosure provides methods and systems for screening or detecting a colorectal cancer or following colorectal disease progression that may be applied to cell-free nucleic acids such as cell-free DNA. The method may use detection of methylation signals within a single sequencing read in identified genomic regions as input features to train a machine learning model and generate a classifier useful for stratifying populations of individuals. The method may comprise extracting DNA from a cell-free sample obtained from a subject, converting the DNA for methylation sequencing, generating sequencing reads, and detecting colon proliferative cell disorder-associated signals in the sequencing information and training a machine learning model to provide a discriminator capable of distinguishing groups in a subject population such as healthy, cancer or distinguishing disease subtype or stage. The method may be used for, e.g., predicting, prognosticating, and/or monitoring response to treatment, tumor load, relapse, or colorectal cancer development.

An expression construct is disclosed which comprises: (i) a DNA sequence which encodes at least one guide RNA (gRNA) operatively linked to a transcriptional regulatory sequence so as to allow expression of the gRNA in a target cell; (ii) a barcode sequence for identification of the at least one gRNA operatively linked to a transcriptional regulatory sequence so as to allow expression of the barcode sequence in the target cell.

Provided herein are methods and composition for processing samples that contain nucleic acids, or cells containing nucleic acids, of a microbiome, using amounts of primers within a range of mole values and rounds of polymerase chain reaction (PCR) within a range of numbers of rounds.