The present disclosure relates, in part, to improved methods of making single-stranded DNA (ssDNA) from double-stranded DNA (dsDNA), as well as use of the resulting ssDNA for genome engineering. The disclosure also relates, in part, to improved methods of genetic modification using single stranded DNA binding proteins.

Colorimetry is used to detect amplification reaction products. A sample is contacted with a reaction mix under conditions such that an amplification reaction occurs and produces an amplification reaction product if the sample contains a target nucleic acid template molecule. The reaction mix includes an enzyme for catalyzing the amplification reaction, and at least one halochromic agent. If the target nucleic acid template molecule is present, the amplification reaction changes the starting pH of the reaction mix to cause a detectable colorimetric change of the halochromic agent, thereby indicating the presence of the target nucleic acid. If the target nucleic acid template molecule is not present, the amplification reaction does not generate an adequate number of protons to sufficiently change the starting pH of the reaction mix to cause a detectable colorimetric change of the halochromic agent, thereby indicating that the amplification reaction product has not been produced.

Colorimetry is used to detect amplification reaction products. A sample is contacted with a reaction mix under conditions such that an amplification reaction occurs and produces an amplification reaction product if the sample contains a target nucleic acid template molecule. The reaction mix includes an enzyme for catalyzing the amplification reaction, and at least one halochromic agent. If the target nucleic acid template molecule is present, the amplification reaction changes the starting pH of the reaction mix to cause a detectable colorimetric change of the halochromic agent, thereby indicating the presence of the target nucleic acid. If the target nucleic acid template molecule is not present, the amplification reaction does not generate an adequate number of protons to sufficiently change the starting pH of the reaction mix to cause a detectable colorimetric change of the halochromic agent, thereby indicating that the amplification reaction product has not been produced.

Herein reported are new tricyclic cytidine compounds, such as 8-diethylamino-tC (8-DEA-tC), that respond to DNA and/or RNA duplex formation with up to a 20-fold increase in fluorescent quantum yield as compared with the free nucleoside, depending on neighboring bases. This turn-on response to duplex formation is by far the greatest of any reported nucleoside analogue that can participate in Watson-Crick base pairing. Measurements of the quantum yield of 8-DEA-tC mispaired with adenosine and, separately, opposite an abasic site show that there is almost no fluorescence increase without the formation of correct Watson-Crick hydrogen bonds. Kinetic isotope effects from the use of deuterated buffer show that the duplex protects 8-DEA-tC against quenching by excited state proton transfer. DFT calculations provide a rationale for the observed photophysical properties that is dependent on duplex integrity and the electronic structure of the analogue.

Herein reported are new tricyclic cytidine compounds, such as 8-diethylamino-tC (8-DEA-tC), that respond to DNA and/or RNA duplex formation with up to a 20-fold increase in fluorescent quantum yield as compared with the free nucleoside, depending on neighboring bases. This turn-on response to duplex formation is by far the greatest of any reported nucleoside analogue that can participate in Watson-Crick base pairing. Measurements of the quantum yield of 8-DEA-tC mispaired with adenosine and, separately, opposite an abasic site show that there is almost no fluorescence increase without the formation of correct Watson-Crick hydrogen bonds. Kinetic isotope effects from the use of deuterated buffer show that the duplex protects 8-DEA-tC against quenching by excited state proton transfer. DFT calculations provide a rationale for the observed photophysical properties that is dependent on duplex integrity and the electronic structure of the analogue.

The invention(s) cover systems and methods for target detection in a multiplexed and rapid manner. Embodiments of the system can include: a base substrate; and an array of sample processing regions defined at a broad surface of the base substrate, wherein each of the array of sample processing regions includes: a set of microwell subarrays arranged in a gradient by volumetric capacity between an upstream end and a downstream end of each respective sample processing region, and a boundary separating each respective sample processing region from adjacent sample processing regions. The system can support methods, with example implementation by an automated platform, for returning preliminary results from a subset of microwells of the samples processing regions, as well as results pertaining to specific and non-specific amplification, for multiple targets of a sample.

The invention(s) cover systems and methods for target detection in a multiplexed and rapid manner. Embodiments of the system can include: a base substrate; and an array of sample processing regions defined at a broad surface of the base substrate, wherein each of the array of sample processing regions includes: a set of microwell subarrays arranged in a gradient by volumetric capacity between an upstream end and a downstream end of each respective sample processing region, and a boundary separating each respective sample processing region from adjacent sample processing regions. The system can support methods, with example implementation by an automated platform, for returning preliminary results from a subset of microwells of the samples processing regions, as well as results pertaining to specific and non-specific amplification, for multiple targets of a sample.

The present disclosure is directed to aptamers comprising a detectable marker situated at an internal location within the aptamer, use of the aptamers to, e.g., detect target analytes, and methods of making the aptamers. In exemplary embodiments, methods of the disclosure comprise contacting the target analyte with an aptamer comprising a detectable marker situated at an internal location within the aptamer, wherein the contacting results in binding of the target analyte to the aptamer, wherein target analyte binding to the aptamer results in restriction of internal rotation of the marker, resulting in a detectable change in the marker.

The present disclosure is directed to aptamers comprising a detectable marker situated at an internal location within the aptamer, use of the aptamers to, e.g., detect target analytes, and methods of making the aptamers. In exemplary embodiments, methods of the disclosure comprise contacting the target analyte with an aptamer comprising a detectable marker situated at an internal location within the aptamer, wherein the contacting results in binding of the target analyte to the aptamer, wherein target analyte binding to the aptamer results in restriction of internal rotation of the marker, resulting in a detectable change in the marker.

Disclosed herein is a method for the detection of the presence of sperm DNA fragmentation in a semen sample. The method comprises a step of embedding the semen sample containing sperm cells in a gel comprising acrylamide, acrylic acid, methacrylic acid, N-isopropylacrylamide (NIPAM), alginate, or polyethylene glycol (PEG), to obtain a sperm cells-embedded gel. A kit for detecting sperm DNA fragmentation in a semen sample is also disclosed.