Oragene dna tubes

Blood (whole blood, WB) and saliva samples were collected at the time of the participants' MRI visits. Saliva was self-collected into the Oragene-DNA tubes (DNA Genotek, Ottawa). Salivary DNA was isolated using the prepIT L2P reagent according to the manufacturer's instruction (DNA Genotek, Ottawa), followed by DNA purification and concentration using the Genomic DNA Clean and Concentrator kit (Zymo Research Corporation, Irvine, CA, USA). Venous blood was collected into EDTA anticoagulant lavender top vacutainer tubes and was transferred on ice to the lab as soon as possible. Extraction of genomic DNA from the WB was performed using the Flexi Gene DNA kit according to the manufacturer's protocol (Qiagen, Germany). CD3⁺ cells (T cells) were isolated from WB using CD3 magnetic beads, accompanying reagents, and the MultiMACS Cell24 separator Plus (all from Miltenyi Biotec, Bergisch-Gladbach, Germany). The Allprep DNA/RNA kit (Qiagen, Germany) was then utilized for DNA extraction from CD3⁺ cells according to the manufacturer's instructions.