Conclusion
Anti-ApoB antibody coated magnetic beads may hold potential for removal of lipoproteins from human PFP prior to EV measurement by NTA but some artefactual effect and EV loss may have to be endured.
Methods
Ten platelet-free plasma (PFP) samples from healthy fasting subjects were incubated with magnetic beads coated with antibodies against apolipoprotein B-48 and B-100 (ApoB). Plasma samples were analysed with NTA before and after application of the bead procedure. Four fasting PFP samples were analysed with an ELISA specific for human ApoB to estimate the degree of removal of lipoproteins and EV array analysis was used for identification of possible EV loss.
Results
The magnetic bead separation procedure resulted in a median reduction of the particle concentration in plasma by 62% (interquartile range 32-72%). The mean size of the remaining particles generally increased. ApoB concentration was reduced to a level close to the background signal, whereas a median reduction of the EV content by 21% (range 8-43%) was observed.