Exosome Isolation: A Technique to Separate Exosomes from the Plasma of Non-small Cell Lung Cancer Patients

- Exosomes are small, membrane-bound vesicles carrying biomolecules like lipids, proteins, DNA, mRNA, and microRNA. Exosomes are released by different cell types into extracellular spaces and can be isolated from biofluids like plasma.

To begin, centrifuge the plasma sample to remove cells and debris. Transfer the plasma supernatant into a fresh tube. Treat the plasma with the desired concentration of ribonuclease enzyme. Incubate the sample on a heating block at 37 degrees Celsius for an appropriate duration.

The enzyme degrades any free RNA in the sample, while the exosomal RNA remains protected. Dilute the sample using PBS. Next, add the desired concentration of Proteinase K enzyme solution and incubate at 37 degrees Celsius for an appropriate time. Proteinase K degrades the bulk of plasma proteins. It also inactivates the previously added ribonuclease enzyme, thereby eliminating the risk of exosomal RNA degradation during downstream processing.

Add a suitable volume of exosome precipitation buffer to facilitate exosome separation from the plasma. Centrifuge the sample to obtain a pellet containing intact exosomes. The isolated exosomes find applications in downstream steps like