Efficient Continuous EV Extraction Workflow from Human Plasma Using ExoFaster-500 Built-In Continuous Mode

1. Overview

This application note evaluates the performance of ExoFaster-500’s dedicated built-in continuous processing mode for repeated loading of identical human plasma samples. Five sequential 1 mL plasma aliquots were loaded under the automatic continuous workflow, which integrates PBS column washing and re-equilibration between each run without manual intervention. NTA particle quantification paired with BCA protein testing, demonstrate highly consistent chromatographic separation, stable EV yield and preserved EV purity across repeated additions, enabling streamlined high-throughput batch processing of plasma EVs.

2. Experimental Protocol

1. Preprocess human plasma by filtration through a 0.45 μm membrane to remove cell debris and particulate impurities.

2. Select the matched SEC column based on sample volume: small column supports up to 10 mL sample loading, large column accommodates up to 25 mL per run.

3. Select the instrument’s built-in continuous mode. This pre-programmed workflow automatically performs full wash and column re-equilibration after each separation cycle.

4. Install column on ExoFaster-500 and load 1 mL plasma sample and initiate automated EV separation and fraction collection.

5. The continuous mode automatically triggers inter-run column cleaning, then proceeds to the next sample run. Repeat the full cycle for 5 consecutive runs using the identical plasma batch.

6. Record absorbance values for each elution fraction; perform NTA particle concentration measurement and BCA total protein quantification.

3. Results

3.1 Overlaid SEC Elution Absorbance Profiles

Absorbance curves generated from all five replicate runs nearly fully overlap across fractions 3–12. Uniform peak retention positions, matching peak shapes and consistent absorbance intensity are observed throughout all runs. No peak drift, signal decay or loss of chromatographic resolution occurs over five sequential separations processed via the built-in continuous mode.

3.2 Quantitative NTA & BCA EV Characterization

Repeat No.	EV Concentration (EV/mL)	Total Protein (mg/mL)	Purity (EV/μg protein)
1	1.59×10¹¹	0.92	1.73×10⁸
2	2.51×10¹¹	1.08	2.33×10⁸
3	4.20×10¹¹	0.97	4.33×10⁸
4	3.03×10¹¹	1.01	3.00×10⁸
5	4.10×10¹¹	0.96	4.28×10⁸

EV particle concentration and particle-to-protein purity metrics remain stable across all five sequential runs. BCA total protein quantification exhibits excellent reproducibility with a low CV of only 6.13%, demonstrating consistent contaminant removal performance across all continuous-mode separations. The integrated washing step within the continuous mode effectively removes residual soluble protein contaminants trapped in the SEC column matrix, sustaining uniform separation performance for repeated identical plasma sample loading.

4. Discussion

Standard SEC EV isolation protocols require column washing between runs even for identical sample batches, as accumulated residual proteins and lipids degrade separation resolution and reduce EV purity over repeated loadings. Most competing EV SEC platforms require manual washing and re-equilibration steps between separations, increasing hands-on operation time and introducing human error.

ExoFaster-500 addresses this limitation with a purpose-built dedicated continuous processing mode. This fully automated workflow eliminates manual column handling by embedding standardized PBS wash and equilibration cycles between each separation run. The integrated washing routine delivers consistent contaminant removal, supporting reliable continuous batch processing of plasma and other identical biological fluid samples without sacrificing separation quality.

5. Conclusion & Recommended Workflow

1. Use ExoFaster-500’s built-in continuous mode for high-throughput repeated EV extraction from identical human plasma samples. The mode automatically completes PBS column washing and re-equilibration between runs, removing the need for manual column maintenance.

2. Five consecutive repeated runs validated that the continuous mode delivers highly reproducible SEC elution profiles, stable EV particle yields and consistent particle-to-protein purity across sequential separations.

3. This automated continuous loading workflow drastically reduces hands-on experimental labor and improves batch processing throughput for plasma EV research.