Qiaamp dna blood mini extraction kit

Genomic DNA was extracted from blood/PBMCs using QIAamp DNA Blood Mini extraction kit (Qiagen, Germany). DNA was quantified by spectrophotometer (ND-1000, Nanodrop Technologies) and the quality was assessed by running on an agarose gel.

Genomic DNA was extracted from venous blood samples using the QIAamp DNA blood mini extraction kit (QIAGEN). APOE gene alleles were determined using TaqMan genotyping assays (App-lied Biosystems (ABI), Foster City, CA, USA) for two single nucleotide polymorphisms (rs429358 and rs7412) and an allelic discrimination method on the ABI 7000 platform [20 (link)].

Genomic DNA was extracted from venous blood samples using QIAamp DNA blood mini extraction kit (Qiagen). The presence of the C9ORF72 expansion was detected using repeat-primed PCR [2 (link)]. Of those testing positive for the expansion, 18 had an excess of 40 repeats, with 3 cases showing an intermediate expansion length between 10 and 40 repeats. Patients were considered negative for the C9ORF72 expansion if their number of repeats was fewer than 10 [2 (link)].

Genomic DNA was extracted from venous blood samples using QIAamp DNA blood mini extraction kit (QIAGEN). The blood sample was obtained in the early diagnostic phase. The presence of the C9orf72 repeat expansion was detected using Repeat‐Primed PCR (RP‐PCR)³. Patients were considered positive for the C9orf72 repeat expansion if the number of repeats were ≥ 30 and negative if the number of repeats was < 30. SNfL concentration and the genetic status of C9orf72 repeat expansion were determined from all patients; 26 were carriers and 52 non‐carriers for the repeat expansion. Mutations in the other FTLD‐associated genes were not systematically screened because the prevalence of these mutations is very low in Finnish patients.²⁴, ²⁵, ²⁶Frozen (−80˚C) serum samples were thawed in room temperature, mixed, centrifuged (10,000g, 5 min, at room temperature), and transferred to a 96‐well plate. The sNfL was quantified using a NfL Advantage kit (REF#: 102258) for the Quanterix single molecule array (SIMOA, Lexington, MA, USA) according to the manufacturer’s instructions.²⁷ All measured values were within the calibration range. The mean intra‐assay CV was 4.6% and the inter‐assay CV was 13.9%.

Ten millilitres of peripheral blood samples were collected from all recruited participants in EDTA tubes. The genomic DNA was extracted from the whole blood samples using the QIAamp DNA Blood Mini Extraction Kit (Qiagen, Hilden, Germany, cat no: 51104) according to the manufacturer’s instructions. DNA purity and concentration were estimated using the Nanodrop 1000 spectrophotometer (Thermo Scientific, USA). All DNA samples were stored at −20°C until further use.