Figure 6.

Schematic view of the micro-NMR technology. Three samples can be applied onto the prototype of the microfluidic cell together with buffer and antibodies. First step in the procedure is a filtration through pores of 50–150 nm after which EV surface antigens are targeted with antibodies labeled with trans-cyclooctene (TCO). For detection 1,2,4,5-tetrazine (TZ) labeled magnetic nanoparticles (MNP) are added and captured EVs are detected with the miniaturized μNMR system. The R ₂ relaxation is equivalent to the amount of MNPs and thereby the amount of surface antigen present in the sample.