Publications & Posters

Preanalytical stability of plasma biomarkers for Alzheimer’s disease pathology

Alzheimer’s & Dementia | May 12, 2023

Sunde AL, Alsnes IV, Aarsland D, Ashton NJ, Tovar-Rios DA, De Santis G, Blennow K, Zetterberg H, Kjosavik SR. 

Alzheimers Dement (Amst). 2023

This study was performed using Simoa Homebrew assay(s).



Plasma tests have demonstrated high diagnostic accuracy for identifying Alzheimer’s disease pathology. To facilitate the transition to clinical utility, we assessed whether plasma storage duration and temperature affect the biomarker concentrations.


Plasma samples from 13 participants were stored at +4°C and +18°C. Concentrations of six biomarkers were measured after 2, 4, 6, 8, 10, and 24 h by single molecule array assays.


Phosphorylated tau 181 (p-tau181), phosphorylated tau 231 (p-tau231), neurofilament light (NfL), and glial fibrillary acidic protein (GFAP) concentrations were unchanged both when stored at +4°C and +18°C. Amyloid-β 40 (Aβ40) and amyloid-β 42 (Aβ42) concentrations were stable for 24 h at +4°C but declined when stored at +18°C for longer than 6 h. This decline did not affect the Aβ42/Aβ40 ratio.


Plasma samples can be stored for 24 h at +4°C or +18°C and result in valid assay results for p-tau181, p-tau231, Aβ42/Aβ40 ratio, GFAP, and NfL.