DNA samples for long-read sequencing library preparations or also 10X genomics linked-reads have to be exceptionally pure. Please see the sample requirements. For difficult DNA samples, especially all plant DNA samples with hard-to-remove contaminants (e.g. some polysaccharides), we recommend to carry out a high-salt/phenol/chloroform cleanup (please see this protocol) . Please note that this protocol often leads to a loss of 50% of the sample. Alternatively the the BorealGenomics Aurora instrument (discontinued but still available, please inquire) can be used. This process is slower though (only a single sample can be processed per day or two days) and is accompanied by similar or greater samples loss.