Capillary Microsampling and Analysis of 4-µL Blood, Plasma and Serum Samples to Determine Human α-Synuclein Elimination Rate in Mice

Abstract

The capillary microsampling technique was scaled down to enable repeated PK sampling of blood, plasma and serum from mice for the determination of the 14-kDa protein α-synuclein using the Gyrolab™ immunoassay platform. 4-µl plasma, serum or blood samples were taken from 36 mice, in total 648 samples were successfully collected and analyzed. Following intravenous administration of human α-synuclein to mice, the elimination of α-synuclein was rapid, with a half-life in plasma of 1.1 h. High endogenous levels in red blood cells in combination with some hemolysis led to a challenge in the evaluation of α-synuclein exposure in plasma and serum. The small sample volumes and flexibility in choice of liquid matrices using the capillary microsampling technique enable repeated sampling in mouse studies, as well as multi-matrix analysis if needed. Liquid microsampling is well suited for micro- and nano-liter scale immunoassays.