GB/T 46972-2026Nanotechnology - Measurement method for the morphology and size of exosomes - Atomic force microscopy (English PDF)

3.1 Extracellular vesicles (EVs)

Membrane particles with a lipid bilayer structure released from cells carry and transfer phospholipids and proteins derived from parent cells.

Including nucleic acids and other contents, they mediate intercellular signal communication and substance exchange.

3.2 exosome

Extracellular structures with membrane structures and generally a size of 30nm to 150nm are produced by "endocytosis, fusion, and release" from living cells.

Vesicles.

3.3

By controlling the distance between the probe and the sample surface through detecting the interaction forces (attractive or repulsive forces) between the probe and the sample surface, surface parameters can be obtained.

Scanning probe microscopy for morphology.

[Source. GB/T 27760-2011, 3.1]

3.4 Tapping mode

One operating mode of atomic force microscopy involves driving a microcantilever via a small piezoelectric element mounted within the microscope's probe holder.

The probe oscillates near its resonant frequency, causing the probe tip to intermittently contact the sample surface, thus achieving morphological imaging.

Note 1.Atomic force microscopes have different operating modes, namely contact mode, non-contact mode and tapping mode.

Note 2.In contact mode, the needle tip is always in contact with the sample, and there is a repulsive force between the needle tip and the sample, which is suitable for highly elastic models or samples that are not easily deformed.

Note 3.In non-contact mode, the needle tip never contacts the sample. The interaction between the needle tip and the sample is a long-range force, and the resolution decreases when the distance between the needle tip and the sample is relatively long.