The invention provides for systems, methods, and compositions for targeting nucleic acids. In particular, the invention provides non-naturally occurring or engineered DNA-targeting systems comprising a novel DNA-targeting CRISPR effector protein and at least one targeting nucleic acid component like a guide RNA. Methods for making and using and uses of such systems, methods, and compositions and products from such methods and uses are also disclosed and claimed.

The present invention relates to improvements in methods of high throughput nucleic acid sequencing, and in particular to improvements to methods of carrying out extension reactions during pairwise sequencing. The present invention relates to a method for carrying out a strand resynthesis extension reaction during pairwise sequencing, wherein said strand resynthesis extension reaction is carried out between a first sequencing read and a second sequencing read, and wherein said strand resynthesis extension reaction extends one or more immobilised primers to copy a first template strand to generate a second immobilised template strand; characterised in that the strand resynthesis extension reaction is carried out using a non-thermostable strand displacement polymerase at a temperature of less than 55° C., preferably at 38° C.

Provided herein are methods for spatial analysis using targeted RNA depletion.

Provided herein are methods for spatial analysis using targeted RNA depletion.

Nucleic acid probes for detection of a target nucleic acid molecule by an RCA reaction in the presence of the target nucleic acid molecule, comprise a first circular template strand which is capable of acting as a template for RCA, and is protected from RCA in the absence of the target nucleic acid molecule by at least a second protector strand which comprises a region of complementarity to the first template strand and is hybridised thereto to form a double-stranded circular structure containing the first template strand inside the protector strand(s). At least one of the second and/or any further protector strands comprises a target binding site, such that upon binding of the probe to the target nucleic acid molecule the probe is able to undergo a strand displacement reaction which allows RCA of the first template strand. Methods of detecting target analytes use such probes.

Nucleic acid probes for detection of a target nucleic acid molecule by an RCA reaction in the presence of the target nucleic acid molecule, comprise a first circular template strand which is capable of acting as a template for RCA, and is protected from RCA in the absence of the target nucleic acid molecule by at least a second protector strand which comprises a region of complementarity to the first template strand and is hybridised thereto to form a double-stranded circular structure containing the first template strand inside the protector strand(s). At least one of the second and/or any further protector strands comprises a target binding site, such that upon binding of the probe to the target nucleic acid molecule the probe is able to undergo a strand displacement reaction which allows RCA of the first template strand. Methods of detecting target analytes use such probes.

Nucleic acid probes for detection of a target nucleic acid molecule by an RCA reaction in the presence of the target nucleic acid molecule, comprise a first circular template strand which is capable of acting as a template for RCA, and is protected from RCA in the absence of the target nucleic acid molecule by at least a second protector strand which comprises a region of complementarity to the first template strand and is hybridised thereto to form a double-stranded circular structure containing the first template strand inside the protector strand(s). At least one of the second and/or any further protector strands comprises a target binding site, such that upon binding of the probe to the target nucleic acid molecule the probe is able to undergo a strand displacement reaction which allows RCA of the first template strand. Methods of detecting target analytes use such probes.

Provided for herein is a method for detecting the presence of a nucleic acid target molecule in a biological sample. In certain aspects, the method comprises contacting a test sample that comprises (i) a biological sample comprising a nucleic acid target molecule and (ii) an osmylated single-stranded oligonucleotide probe comprising at least one pyrimidine residue covalently bonded to a substituted or unsubstituted Osmium tetroxide (OsO.sub.4)-2,2′-bypyridine group (OsBp group).

Provided for herein is a method for detecting the presence of a nucleic acid target molecule in a biological sample. In certain aspects, the method comprises contacting a test sample that comprises (i) a biological sample comprising a nucleic acid target molecule and (ii) an osmylated single-stranded oligonucleotide probe comprising at least one pyrimidine residue covalently bonded to a substituted or unsubstituted Osmium tetroxide (OsO.sub.4)-2,2′-bypyridine group (OsBp group).

Methods and kits for depleting amplicons that correspond to undesired RNA species present in a sample are provided. The disclosed methods and kits employ a blocker that anneals with at least a portion of the undesired RNA, resulting in a duplex that is not a suitable substrate for ligating an adapter to the end of the undesired RNA.