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. |