P tau181 advantage v2 kit

Blood samples were drawn by the laboratory technician. Fasting venous blood was drawn from all subjects between 8 am and 10 am and collected in tubes containing ethylenediaminetetraacetic acid (EDTA). Samples were then centrifuged at 3000 × g for 10 min at 4°C to obtain plasma within 2 h of collection. The plasma was stored at −80°C until biochemical analysis. All measurements were performed on the Simoa HD-X analyser platform (Quanterix, Lexington, MA). Plasma Aβ42, Aβ40, and t-tau levels were measured using the Quanterix Simoa Neurology 3-Plex A Advantage kit (Lot 503205), and p-tau181 levels were measured using the p-tau181 Advantage V2 kit (Lot 502793), all according to the manufacturer’s instructions and standard procedures. The lower limits of detection of the Aβ42, Aβ40, t-tau, and p-tau181 assays were 0.045, 0.196, 0.019, and 0.028 pg/mL, whereas the lower levels of quantification were 0.142, 0.675, 0.063, and 0.338 pg/mL, respectively. The coefficients of variation for Aβ42, Aβ40, t-tau, and p-tau181 were 5.0%, 9.7%, 6.2%, and 4.7%, respectively. Samples were diluted 4× and tested in duplicate by the automatic HD-X analyser. Two quality control samples were run on each plate for each analyte.

Plasma and CSF were collected and β-Amyloid 1–42 (Aβ42), β-Amyloid 1–40 (Aβ40), neurofilament light chain (NfL), and glial fibrillary acidic protein (GFAP) concentrations were measured by Neurology 4-plex E Kit (Cat. No. 103,670) with sensitive Single molecule array (Simoa) technique (Quanterix Corp., Billerica, MA, USA). And p-tau-181 was measured by p-tau-181 Advantage V2 Kit (Cat. No. 103,714) assessed with Simoa technology.

We measured the plasma level of sST2 in 613 individuals from Chinese_cohort_1 (n = 277 individuals with AD, n = 336 HCs); CSF level of sST2 in 86 individuals from the UKBBN cohort (n = 75 individuals with AD, n = 11 HCs); and the level of sST2 secreted by hCMEC/D3 cells using the Human ST2/IL-33 R Quantikine ELISA Kit (DST200; R&D Systems). The plasma levels of NfL (n = 154 individuals with AD, n = 135 HCs) and P-tau181 (n = 156 individuals with AD, n = 134 HCs) in individuals from Chinese_cohort_1 were measured by the Quanterix Accelerator Laboratory using the Quanterix NF-light SIMOA Assay Advantage Kit (103186) and P-Tau 181 Advantage V2 Kit (103714), respectively⁹³ .