A double-stranded DNA to be analyzed is analyzed without subjecting it to a modification treatment. An adapter molecule to be bound to the double-stranded DNA to be analyzed has a double-stranded nucleic acid region having base sequences complementary to each other, a pair of single-stranded nucleic acid regions having base sequences non-complementary to each other, and a block molecule placed in one of the single-stranded nucleic acid regions.

The present disclosure provides methods and compositions for determining the presence of microorganisms in biological fluids by processing extracellular vesicles. The fluids are treated with a composition comprising a pH buffer, a nonionic surfactant, a zwitterionic detergent, an anionic surfactant, and a reducing agent. This treatment solubilizes extracellular vesicles in the fluid, enhancing the ability of diagnostic tools to find the microorganisms. The extracellular vesicles may also be isolated before solubilizing.

The present disclosure provides methods and compositions for determining the presence of microorganisms in biological fluids by processing extracellular vesicles. The fluids are treated with a composition comprising a pH buffer, a nonionic surfactant, a zwitterionic detergent, an anionic surfactant, and a reducing agent. This treatment solubilizes extracellular vesicles in the fluid, enhancing the ability of diagnostic tools to find the microorganisms. The extracellular vesicles may also be isolated before solubilizing.

The present disclosure provides a novel approach, recomSELEX, that highly integrate mutually supportive recombination and computational methods for aptamer selection and identification. The recomSELEX approach comprises a recombinatorial SELEX platform for aptamer screening that exponentially increases the sequence space that is explored by incorporation of a DNA shuffling step that allows recombination between aptamers. Subsequently, the recombinatorial SELEX platform can also be employed to develop new and optimize already existing aptamers. The recomSELEX further comprises a computational SELEX platform with a constrained genetic algorithm (GA) to identify potential aptamers that are stable and have the desired specificity and affinity of a target.

The present disclosure provides a novel approach, recomSELEX, that highly integrate mutually supportive recombination and computational methods for aptamer selection and identification. The recomSELEX approach comprises a recombinatorial SELEX platform for aptamer screening that exponentially increases the sequence space that is explored by incorporation of a DNA shuffling step that allows recombination between aptamers. Subsequently, the recombinatorial SELEX platform can also be employed to develop new and optimize already existing aptamers. The recomSELEX further comprises a computational SELEX platform with a constrained genetic algorithm (GA) to identify potential aptamers that are stable and have the desired specificity and affinity of a target.

The invention provides xeno-nucleic acid particle display libraries, methods for identifying functional non-natural nucleic acid (XNA) aptamers using the particle display libraries, and compositions comprising XNA aptamers identified by screening candidate molecules using the xeno-nucleic acid particle display libraries.

The invention provides xeno-nucleic acid particle display libraries, methods for identifying functional non-natural nucleic acid (XNA) aptamers using the particle display libraries, and compositions comprising XNA aptamers identified by screening candidate molecules using the xeno-nucleic acid particle display libraries.

A method for determining nitric oxide concentration in biological samples. The method includes for determining nitric oxide concentration in a sample including: (i) providing a nucleic acid complex comprising a first single-stranded nucleic acid molecule comprising a fluorophore crosslinked to the first strand, the fluorophore comprising diaminorhodamine-4-methylamine (DAR-4M) conjugated, to dibenzocyclooctyne-polyethylene glycol (DBCO-PEGn) linker, wherein n equals 4-12 and a second single-stranded nucleic acid molecule that is partially or fully complementary to the first single-stranded molecule, wherein the nucleic acid complex further comprises a first label and a targeting moiety conjugated to the first single-stranded nucleic acid molecule or the second single-stranded nucleic acid molecule, the first label is capable of producing a signal, wherein the intensity of the signal is dependent at least on concentration of the nucleic acid complex in the sample; (ii) contacting the sample with the nucleic acid complex; (iii) measuring the intensity of the signal: and (iii) determining the nitric oxide concentration from the measured signal. Compositions for determining nitric oxide concentrations in biological samples are also included.

A method for determining nitric oxide concentration in biological samples. The method includes for determining nitric oxide concentration in a sample including: (i) providing a nucleic acid complex comprising a first single-stranded nucleic acid molecule comprising a fluorophore crosslinked to the first strand, the fluorophore comprising diaminorhodamine-4-methylamine (DAR-4M) conjugated, to dibenzocyclooctyne-polyethylene glycol (DBCO-PEGn) linker, wherein n equals 4-12 and a second single-stranded nucleic acid molecule that is partially or fully complementary to the first single-stranded molecule, wherein the nucleic acid complex further comprises a first label and a targeting moiety conjugated to the first single-stranded nucleic acid molecule or the second single-stranded nucleic acid molecule, the first label is capable of producing a signal, wherein the intensity of the signal is dependent at least on concentration of the nucleic acid complex in the sample; (ii) contacting the sample with the nucleic acid complex; (iii) measuring the intensity of the signal: and (iii) determining the nitric oxide concentration from the measured signal. Compositions for determining nitric oxide concentrations in biological samples are also included.

The invention provides methods, compositions, kits and devices for the detection of target molecules. In some embodiments, the invention allows for multiplexed target molecule detection.