title: Human sputum
organism: prokaryotic environmental samples
description: Smear-positive and culture-positive TB sputum samples were collected from 22 patients (13 males and eight females, ages between 20 and 66; data missing for one patient). Control sputum samples were also collected from 14 individuals (six males and eight females, ages between 22 and 82) with TB-resembling coughing symptoms but being culture-negative for comparison. Sputum samples were treated with a 3% NaOH solution, neutralized with a phosphate buffer and then centrifuged. About 200 µl supernatant was subjected to genomic DNA extraction using the QIAamp DNA Mini Kit.