Nanoparticle Tracking Analysis for Exosome Characterization: Size, Concentration & Marker Profiling

What Is NTA-Based Exosome Identification

Nanoparticle Tracking Analysis (NTA) is a high-resolution technique for the characterization of extracellular vesicles (EVs), including exosomes, based on particle-by-particle tracking in liquid suspension. It enables absolute quantification and size distribution analysis, offering critical insights for R&D, formulation development, and process monitoring.

Creative Proteomics leverages NTA technology to deliver actionable metrics such as particle concentration (particles/mL), modal diameter, D10/D50/D90, and—via fluorescence labeling—marker-specific subpopulation detection (e.g., CD9⁺/CD63⁺/CD81⁺ EVs). This makes NTA especially valuable for users validating isolation methods, assessing sample integrity, or benchmarking EV-enriched preparations.

How Nanoparticle Tracking Analysis Works in Exosome Profiling

NTA is based on the principle of Brownian motion, where particles suspended in a fluid exhibit random motion. A laser beam illuminates the sample, and a sensitive camera captures the light scattered by each particle as it moves within a defined observation volume.

The software tracks multiple particle trajectories in real time and calculates their hydrodynamic diameter using the Stokes-Einstein equation, which relates particle displacement to size. This enables simultaneous sizing and counting of individual particles with high precision.

Because NTA analyzes particles individually, it can resolve polydisperse and heterogeneous populations, which are common in EV preparations. Two operational modes are typically used for exosome analysis:

• Brightfield (Conventional) NTA – Measures size and concentration of all detectable particles.
• Fluorescence NTA (fl-NTA) – Tracks only particles labeled with fluorescent markers, allowing for surface-marker-specific profiling (e.g., CD63⁺ vesicles).

What's Included in Our Exosome NTA Service

Particle Size and Concentration Analysis (Brightfield NTA)

• Measures hydrodynamic diameter (mean, mode, D10/D50/D90)
• Provides absolute particle concentration (particles/mL)
• Generates size distribution histograms
• Performed with multiple replicates for statistical reliability

Fluorescent NTA for Marker-Positive EV Subsets

• Detects CD9⁺, CD63⁺, CD81⁺ or other fluorescently labeled exosome populations
• Compatible with multiple laser channels (405, 488, 532, 640 nm)
• Supports antibody or dye-based labeling
• Includes negative/isotype control validation
• Delivers subpopulation-specific size and count metrics

Zeta Potential Measurement

• Evaluates surface charge (ζ-potential) of exosomes
• Useful for stability assessment, formulation screening, and colloidal behavior profiling

Advantages of Our NTA Service

High-Precision Quantification

Accurate exosome concentration reporting with ±10% variance across replicates, ensuring reliable batch-to-batch comparison.

Validated Replicability

Every sample is measured in triplicate video recordings with strict QC checks, reducing variability and enhancing reproducibility.

Single-Particle Resolution

Detects particles as small as 30 nm, capturing size heterogeneity that bulk techniques like DLS cannot resolve.

Calibrated and Standardized Workflow

Instruments calibrated with traceable nanoparticle standards ensure consistent sizing and concentration results across different runs and projects.

Fluorescence-Enabled Specificity

fNTA supports up to 4 excitation channels (405/488/532/640 nm) for simultaneous detection of marker-positive exosomes (e.g., CD9, CD63, CD81).

Decision-Ready Data Packages

Clients receive publication-quality plots, structured datasets (CSV/JSON), and optional raw videos, making results integration-ready for R&D, QC, or publication.

Nanoparticle Tracking Analysis Platform & Technical Specifications

Technical Specifications Optimized for Exosome Analysis

Platform Highlights

• Wide Particle Detection Range: Capable of resolving nanoparticles from 30 nm to 1,000 nm, covering exosomes, microvesicles, and protein aggregates.
• Real-Time Video Tracking: Direct visualization of Brownian motion, enabling particle-by-particle measurement instead of bulk averages.
• Multi-Laser Fluorescence Support: Equipped with 405, 488, 532, and 640 nm excitation channels, enabling optional marker-specific detection via fluorescent dyes or antibody conjugates.
• Zeta Potential Option: Extendable to surface charge analysis, providing additional insights into sample stability.
• Temperature Control: Built-in 20–40 °C regulation, ensuring consistent measurements across varying sample conditions.
• Flexible Sample Input: Supports small sample volumes (≥500 µL), compatible with diverse biological matrices such as plasma, serum, or conditioned media.

Sample Requirements for NTA-Based Exosome Identification

Requirement	Details
Accepted Sample Types	Conditioned Media, Serum/Plasma, Urine/CSF, Purified EV Fractions, Other Biological Fluids (contact us for custom analysis)
Sample Volume	Minimum 500 µL per sample for full analysis (Brightfield NTA + optional Fluorescent NTA). Larger volumes required for higher concentration samples or batch studies.
Sample Preparation	Pre-clarification (optional 0.22 µm filtration); Dilution for optimal particle count (20–100 particles/frame)
Storage	Store at 4°C for up to 24 hours; For longer storage, snap freeze and ship on dry ice
Shipping Instructions	Ship with cold packs or dry ice. Avoid freeze-thaw cycles. Ensure samples are well-packed for temperature stability.
Additional Notes	Provide a sample information sheet detailing sample type, matrix, isolation method, and any specific conditions for analysis. If using fNTA, provide antibodies/dyes used for labeling.

What You'll Receive

• Comprehensive report: Objectives, methods, sample details, instrument settings, and QA summary.
• Quantitative results: Concentration (particles/mL), modal diameter, D10/D50/D90, full distributions.
• Fluorescent metrics (if selected): Marker-positive concentration, fraction of total, size profiles of labeled subpopulations.
• Data packages: CSV/JSON exports; raw videos on request; figure-ready PNG/PDF plots.

Size Distribution Histogram

The size distribution histogram displays the particle size range of exosomes, highlighting the modal diameter and size distribution within the sample.

Particle Concentration & Tracking Snapshot

This snapshot illustrates particle concentration and real-time particle tracking, showcasing the movement paths of individual particles during NTA analysis.

Fluorescence NTA Histogram (Marker-Positive)

The fluorescence NTA histogram compares the size distribution of marker-positive exosomes (e.g., CD63+) with unmarked exosomes, demonstrating the specificity of fluorescence labeling.

Zeta Potential Distribution

The zeta potential distribution curve illustrates the surface charge of exosomes, providing critical information about their stability and potential aggregation risk.

NTA vs Other Techniques – Which Is Right for You?

Real-World Case Highlights