Zetasizer nano zs 90 particle size analyzer

Exosomes were isolated by differential velocity centrifugation. In brief, culture medium was initially subjected to centrifugation at 300 × g for 10 min, 2,000 × g for 10 min and 10,000 × g for 30 min at 4°C. The supernatant was further subjected to centrifugation at 100,000 × g for 70 min at 4°C, and pellets rich in exosomes were resuspended in 1X PBS. To identify the isolated exosomes, the particle size of exosomes was initially determined by Zetasizer Nano ZS 90 particle size analyzer (Malvern Panalytical), and the morphology of the exosomes was observed under a transmission electron microscope (Leica Microsystems GmbH; magnification, ×40,000). As described previously (33 (link)), 10 µl of sample was added to a 2-mm copper mesh grid and the excess PBS was removed with a filter paper. Then, 10 µl of phosphotungstate (20 g/l) was added to the copper net for negative staining for 2 min and grilled under an incandescent lamp for 5 min. The isolated samples were subjected to 10% SDS-PAGE, and western blotting was used to detect the marker proteins TSG101 and CD63 on exosomes.

The ¹H-nuclear magnetic resonance (¹H-NMR) spectra were recorded in DMSO-d₆ on a Bruker Spectrospin Avance 400 MHz NMR spectrophotometer. Chemical shifts are given in ppm downfield from tetramethylsilane. Infrared (IR) spectra were measured on a Perkin Elmer Spectrum One spectrophotometer. UV-vis absorption spectra were recorded on a Cary 60 UV-vis spectrophotometer (Agilent Technologies). High resolution mass spectrometry (HRMS) was carried out using an Agilent 6520 Q-TOF LC/MS mass spectrometer. Elemental analysis was performed on a Perkin-Elmer 240 elemental analyzer. Fluorescence spectra and resonance light scattering (RLS) spectra were measured at room temperature using a SHIMADZU RF-5301PC spectrofluorimeter. The transmission electron micrograph (TEM) images were recorded on a German Leica TCS-SP8 transmission electron microscope. A Malvern Zetasizer Nano ZS90 particle size analyzer was used for dynamic light scattering (DLS) studies.