This method has become popular in exosomal isolation in recent years. The reagents used for polymer-based exosomes isolation mainly include protamine, acetate, protein organic solvent precipitation (PROSPR), polyethylene (PEG), among which PEG is the most common.

Polymer-based precipitation is a cost-effective method widely used in different research fields. The percentage of the polymer should be modified in different cell types or liquid biopsy before precipitation.

The precipitation-based techniques for exosome isolation are popular in clinical research because they cause less damage to exosomes and require less specialized equipment.

Several different precipitation approaches were developed for exosome isolation, including charge-based precipitation methods, as well as precipitation with organic solvents and neutral polymers, such as polyethylene glycol (PEG).

In exosome-based applications, methods for isolating and purifying exosomes provide the greatest hurdle. The recovery and specificity of each approach differ, but their use depends upon the application area.