Abstract: The invention pertains to a method for labelling a target nucleic acid fragment using a combination of a site-specific nuclease and a reverse transcriptase. The labelling results in the addition of a specific nucleotide sequence to at least one free 3?-end of the target nucleic acid fragment. The invention further relates to a method for determining the sequence of the target nucleic acid fragment as well as construct and kit for use in the method of the invention.

Abstract: The current invention pertains to adapters comprising a protelomerase recognition sequence, preferably a TeIN protelomerase recognition sequence. The adapters of the invention can be used for the preparation of a nucleic acid molecule library. The invention also relates to a method for producing a nucleic acid molecule library using one or more adapters comprising a protelomerase recognition sequence. The adapters may be contacted with a protelomerase to cleave and close the ends of the adapters. Said closed adapters are e.g. protected against exonuclease treatment. The method of the invention further concerns an amplification method and a sequencing method using adapters having a protelomerase recognition sequence.

Abstract: The invention pertains to a method for isolating a nucleic acid, wherein the nucleic acid is stabilized in a hydrogel. The hydrogel can be dissolved to release the nucleic acid without breaking the molecule. A preferred hydrogel is alginate. The invention further concerns a method for sequencing the nucleic acid and a composition comprising the hydrogel and the nucleic acid.

Abstract: The current invention pertains to a method for the enrichment of a target nucleic acid fragment from a nucleic acid sample, comprising the steps of cleaving the nucleic acid sample with a first and a second RNA guided or DNA guided endonuclease complex, preferably a first and a second gRNA-CAS complex, thereby generating the target nucleic acid fragment and at least one non-target nucleic acid fragment. The generated fragments are subsequently contacted with an exonuclease, wherein the exonuclease digests only the non-target nucleic acid fragments. The invention further pertains to the use of the enriched target nucleic acid fragments for preparing an adapter ligated target nucleic acid fragment and for sequencing the target nucleic acid fragment.

Abstract: The current invention pertains to a reliable method for determining the relative frequency of a sequence variant of interest in a nucleic acid sample derived from at least one polyploid cell, wherein the method uses a UMI to correct for any amplification biases. The invention further pertains to the use of a UMI for accurately determining the relative frequency of a sequence variant of interest in a nucleic acid sample derived from at least one polyploid cell.