The present disclosure relates to methods and apparatus for synthesising polynucleotides such as DNA and RNA in the absence of a template, to polynucleotides synthesised therefrom and to a kit of parts for synthesising polynucleotides.

Described herein are compositions that may be used to detect viral nucleic acid. For example, these compositions may comprise a DNA-nanostructure, a capture oligonucleotide and a protector oligonucleotide, wherein the components are designed based on a duo-toehold-mediated displacement reaction (duo-TMDR) strategy. In this strategy, a first TMDR can switch off a Faster resonance energy transfer (FRET) process and a second TMDR can release the target viral nucleic acid and amplify the signal. Methods of using such compositions are also provided herein.

Described herein are compositions that may be used to detect viral nucleic acid. For example, these compositions may comprise a DNA-nanostructure, a capture oligonucleotide and a protector oligonucleotide, wherein the components are designed based on a duo-toehold-mediated displacement reaction (duo-TMDR) strategy. In this strategy, a first TMDR can switch off a Faster resonance energy transfer (FRET) process and a second TMDR can release the target viral nucleic acid and amplify the signal. Methods of using such compositions are also provided herein.

Described herein are methods and compositions that provide highly efficient nucleic acid amplification and signal detection using a cycling probe. In some embodiments, this allows a 3-fold or greater increase of amplification product for each amplification cycle and therefore increased sensitivity and speed over conventional PCR. Modified bases can be employed in primers to provide this base-3 or greater amplification with satisfactory PCR cycle times, which are improved, as compared to those observed in the absence of modified bases.

Described herein are methods and compositions that provide highly efficient nucleic acid amplification and signal detection using a cycling probe. In some embodiments, this allows a 3-fold or greater increase of amplification product for each amplification cycle and therefore increased sensitivity and speed over conventional PCR. Modified bases can be employed in primers to provide this base-3 or greater amplification with satisfactory PCR cycle times, which are improved, as compared to those observed in the absence of modified bases.

The disclosure provides a method for detecting a target analyte in a biological sample including contacting the sample with one or more probe sets each comprising a primary probe and a linker, contacting the sample with an initiator sequence, contacting the sample with a plurality of fluorescent DNA hairpins, wherein the probe binds the target molecule, the linker connects the probe to the initiator sequence, and wherein the initiator sequence nucleates with the cognate hairpin and triggers self-assembly of tethered fluorescent amplification polymers, and detecting the target molecule by measuring fluorescent signal of the sample.

The disclosure provides a method for detecting a target analyte in a biological sample including contacting the sample with one or more probe sets each comprising a primary probe and a linker, contacting the sample with an initiator sequence, contacting the sample with a plurality of fluorescent DNA hairpins, wherein the probe binds the target molecule, the linker connects the probe to the initiator sequence, and wherein the initiator sequence nucleates with the cognate hairpin and triggers self-assembly of tethered fluorescent amplification polymers, and detecting the target molecule by measuring fluorescent signal of the sample.

In certain aspects, the invention disclosed herein relates to the isothermal amplification of probe linkage products to generate specific amplified signals. In some aspects, the invention provides methods, reagents, and kits for carrying out such amplification via the isothermal chain reaction (ICR).

In certain aspects, the invention disclosed herein relates to the isothermal amplification of probe linkage products to generate specific amplified signals. In some aspects, the invention provides methods, reagents, and kits for carrying out such amplification via the isothermal chain reaction (ICR).

The present disclosure describes technologies that permit sensitive detection of nucleic acids of interest (i.e., nucleic acids whose nucleotide sequence is or includes a target sequence).