OPRL1 and cystic fibrosis: In our hands, the BioMérieux easyMAG Nuclisens protocol Generic 2.0.1, combined with proteinase K pretreatment, was the DNA-extraction protocol that enabled the most sensitive detection of P. aeruginosa from sputum of CF patients, both with conventional and with qualitative PCR, giving amplification of the P. aeruginosa oprL target gene up to dilutions 6 and 8, respectively.