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Updated: Jul 12, 2026
An Innovative Method for Exosome Quantification and Size Measurement
Published on: January 17, 2015
A Novel Fully Automatic Free-Flow Isoelectric Focusing System and Its Application in the Large-Scale Isolation of
Yaoguo Wang1,2, Shuai Qi2,3, Qiang Zhang2,3
1Faculty of Chemical Engineering and Energy Technology, Shanghai Institute of Technology, Shanghai, China.
None:
Free-flow electrophoresis is a core technology for biological particle separation, but traditional devices suffer from low automation, poor flow stability, and limited throughput, hindering industrial-scale applications. Herein, a novel fully automatic reciprocating free-flow isoelectric focusing (RFFIEF) system, a batch-type of automated closed-loop free-flow isoelectric focusing (FFIEF), was developed, integrating a 24-channel separation chamber, closed gas-liquid circulation drive, and intelligent control system to achieve unattended standardized operation. Standard protein verification showed excellent flow stability and pH gradient reproducibility (pooled standard deviation [SD] = 0.19 pH units excluding ampholyte-induced outliers). The system was applied to large-scale separation of milk exosomes, which were effectively focused at pH 5.0-7.5. Exosome subpopulations were fractionated by surface charge: CD81-positive subpopulations concentrated at pH 5.8-6.5, whereas CD63-positive subpopulations were highly enriched at pH 6.9. This system breaks through the automation bottleneck of conventional devices, providing an efficient platform for large-scale biological particle separation with broad industrial prospects.
