Table 1.

Extracellular vesicle (EV) isolation techniques.

Isolation Method	Procedure	Advantages	Disadvantages
Differential Ultracentrifugation (UC)	The different molecules in a fluid sample are separated by centrifugation at high g-forces. Can be combined with sucrose density gradients or SEC for higher purity.	As the gold standard for EVs isolation, it is a cheap and scalable technique.	Low-yield technique with a time-consuming protocol, difficult to automatize. Moreover, specialized instruments and training are needed. EVs may collapse and the resulting sample is usually contaminated.
Size-Based Filtration, Chromatography and Fractionation	Technique based on a column filled with different sized pores. Smaller size molecules will have to go through many pores while larger molecules will be faster eluted.	Fast (normally a single step) and automatable method with high purity and integrity of the resulting sample.	The type of membrane used can have a large impact on the quality of the isolated EVs.
Immunoaffinity	Selective antibody-mediated arrest of EVs with specific surface antigens.	Allows a more selective isolation of EVs.	Protocols for immunoaffinity procedure are set on a very small scale and the costs for large volume samples isolation are high. Also, it is hard to recover fully intact EVs.
Polymer precipitation	The sample containing the EVs is precipitated with a solution of PEG and concentrated by centrifugation	Easy, scalable technique that does not require long runs or specific equipment.	The purity of the sample obtained should be improved. It is frequent to have samples contaminated with other particles and proteins.
Microfluidic separation	This method uses different techniques like immunoaffinity or filtrations to isolate EVs.	Fast technique with high sensitivity and efficiency.	This method presents a low sample volume restriction and needs expensive devices.