Alzheimer's disease biomarkers in cerebrospinal fluid are stable with the Elecsys immunoassay to most pre-analytical influencing factors except freezing at -80 °C.

Measurements of the concentrations of Aß42, P-tau, and T-tau in CSF with use of the Elecsys immunoassay are robust to the pre-analytical influencing factors of blood contamination and duration of storage. Freezing at -80 °C results in significant reduction of biomarker concentrations regardless of the storage tube and must be considered in retrospective analysis.