Topographic Imaging of Trypanosoma cruzi Extracellular Vesicles

Topographic imaging of the EV of T. cruzi was performed using the non-contact AFM mode in an NX-20 instrument (Park Systems, Suwon, Korea) with ACTA cantilevers (K = 40 N m^–1 and f = 320 kHz), as previously described^{13 (link)}. Briefly, each EV sample was diluted 1:4 in sterile-filtered PBS and 8 µL of the dilution of EV was deposited onto freshly cleaved muscovite mica. After 10 min, the substrate with the sample was rinsed three times with MilliQ water (Millipore, Burlington, MA, USA) and further dried with a gentle stream of argon. Images were typically acquired as 256 × 256 pixels at a scan rate of 0.5–0.7 Hz, and processed and analyzed using XEI software (Park Systems, Suwon, Korea). Representative images of samples were obtained by scanning at least 3 different locations on at least 3 different samples.