The invention provides an exonuclease or an enzymatically active fragment thereof, said exonuclease having the amino acid sequence of SEQ ID No. 1 or an amino acid sequence which is at least about 50% identical thereto, wherein said exonuclease or enzymatically active fragment thereof (i) is substantially irreversibly inactivated by heating at a temperature of about 55° C. for 10 minutes in a buffer consisting of 10 mM Tris-HCl, pH 8.5 at 25° C., 50 mM KCl and 5 mM MgCl.sub.2; (ii) is substantially specific for single stranded DNA; and (iii) has a 3′-5′ exonuclease activity. The invention further provides a method of removing single stranded DNA from a sample, a method of nucleic acid amplification, a method of reverse transcription and a method of nucleic acid sequence analysis in which the exonuclease or enzymatically active fragment thereof is used. The invention still further provides nucleic acids encoding said exonuclease or an enzymatically active fragment thereof and kits or compositions comprising the same.

Disclosed herein are methods for detecting presence of a nucleotide variant in a target nucleic acid utilizing a nuclease protection assay. The methods include contacting a sample with at least two probes, wherein the first probe is complementary to the wild-type (non-variant) nucleotide(s) at the nucleotide variant position(s) in the target nucleic acid and the second probe is complementary to the variant nucleotide(s) at the nucleotide variant position(s) in the target nucleic acid, under conditions sufficient for the probes to hybridize to the target nucleic acid, producing a mixture of hybridized and unhybridized nucleic acids. The mixture is contacted with a nuclease specific for single-stranded nucleic acid molecules under conditions sufficient to remove unhybridized nucleic acid molecules (or unhybridized portions of nucleic acid molecules). The presence of the at least two probes is then detected, thereby detecting the presence of the variant and/or non-variant target nucleic acid in the sample.

Disclosed herein are methods for detecting presence of a nucleotide variant in a target nucleic acid utilizing a nuclease protection assay. The methods include contacting a sample with at least two probes, wherein the first probe is complementary to the wild-type (non-variant) nucleotide(s) at the nucleotide variant position(s) in the target nucleic acid and the second probe is complementary to the variant nucleotide(s) at the nucleotide variant position(s) in the target nucleic acid, under conditions sufficient for the probes to hybridize to the target nucleic acid, producing a mixture of hybridized and unhybridized nucleic acids. The mixture is contacted with a nuclease specific for single-stranded nucleic acid molecules under conditions sufficient to remove unhybridized nucleic acid molecules (or unhybridized portions of nucleic acid molecules). The presence of the at least two probes is then detected, thereby detecting the presence of the variant and/or non-variant target nucleic acid in the sample.

Processes and kits for preparing a plurality of multiplex amplification products for targeted next generation-sequencing providing reduced background noise.

Processes and kits for preparing a plurality of multiplex amplification products for targeted next generation-sequencing providing reduced background noise.

Kits and methods for enriching target nucleic acid sequences, such as nucleic acid molecules including the target nucleic acid sequence, and kits and methods for depleting target nucleic acid sequences, such as nucleic acid molecules including the target nucleic acid sequences. In an embodiment, the methods for enriching target nucleic acid sequences include selectively degrading single-stranded sample nucleic acid molecules, such as those that do not include the target nucleic acid sequences. In an embodiment, the methods for depleting target nucleic acid sequences include selectively degrading double-stranded sample nucleic acid molecules, such as those including the target nucleic acid sequence.

Kits and methods for enriching target nucleic acid sequences, such as nucleic acid molecules including the target nucleic acid sequence, and kits and methods for depleting target nucleic acid sequences, such as nucleic acid molecules including the target nucleic acid sequences. In an embodiment, the methods for enriching target nucleic acid sequences include selectively degrading single-stranded sample nucleic acid molecules, such as those that do not include the target nucleic acid sequences. In an embodiment, the methods for depleting target nucleic acid sequences include selectively degrading double-stranded sample nucleic acid molecules, such as those including the target nucleic acid sequence.

The disclosure provides, for example, single stranded, covalently closed DNA that does not form a double stranded structure longer than 100 base pairs. The ssDNA may encode an effector sequence, for instance a therapeutic protein. The ssDNA may comprise a nuclear targeting sequence (NTS). In some embodiments, the ssDNA shows decreased activation of the innate immune system compared to an otherwise similar dsDNA.

The disclosure provides, for example, single stranded, covalently closed DNA that does not form a double stranded structure longer than 100 base pairs. The ssDNA may encode an effector sequence, for instance a therapeutic protein. The ssDNA may comprise a nuclear targeting sequence (NTS). In some embodiments, the ssDNA shows decreased activation of the innate immune system compared to an otherwise similar dsDNA.

A nucleic acid patch method for amplifying target nucleic acid sequences in circulating free DNA or residual DNA samples where the defining ends of the target nucleic acid sequences are unknown.