Antibody-Based Assays for Phenotyping of Extracellular Vesicles

Table 1

Characteristics of the antibody-based assays reviewed here.

Technique	Purification	Optimized to analyse	Sample	Timeframe	Multiplexing; (markers/samples)	Output
Flow cytometry	±centrifugation	EVs ≥ 300 nm	50–100 µL	Hours	Limited/1	Size distribution, phenotype, enumeration
EV Array	None	Exosomes	≥10 µL	Days	60/20	Relative quantification of amount and phenotype
SPRi microarray	None	Exosomes	5 µL/s	Minutes	Several (Limit not indicated)/1	Relative quantification of amount and phenotype
nPLEX	Filtration ± centrifugation	Exosomes	12 µL	Minutes	Prototype 1/12 or 12/1 (scalable)	Relative quantification of amount and phenotype
NMR	Filtration + centrifugation	Exosomes	1 µL (pelleted EVs)	Minutes	1/3	Relative quantification of amount and phenotype
Bead-based microfluidic	None	Exosomes	≥30 µL	Hours	1/1	Quantification of phenotype (surface and IC)

Preanalytical purification procedures not included.  Ultracentrifugation and density gradient centrifugation are often required when exosomes are analyzed by flow cytometry; however, when analyzing MVs, preanalytical purification is not always performed.