Dual-Laser EV App Note — expand fluorochrome selection and experimental possibilities with two excitation wavelengths.
Get the Note →VesiRef CD63 GFP App Note — quantifying size, concentration, and cargo of a fluorescent EV subpopulation.
Get the Note →What to Measure
Four critical quality attributes of extracellular vesicles
EVs carry real therapeutic and diagnostic potential, but realizing it demands accurate measurement. Size, concentration, surface phenotype, and cargo each influence how EVs behave in vivo — and how reproducibly your science holds up.
Quality Attribute 01 & 02
Accurate EV size & concentration — where NTA falls short
MRPS reproduces the expected power-law relationship between EV size and concentration, consistent with TEM. NTA underestimates the concentration of small particles in the presence of larger ones.
The limitation
NTA tracks Brownian motion optically, which reduces its sensitivity to small particles whenever larger, brighter particles are present in the same sample. The result is a systematic undercount of the small-particle population — the majority of most EV preparations.
With MRPS
MRPS detects each particle electrically as it displaces current through a microfluidic constriction. Signal amplitude is proportional to particle volume — independent of optical properties, refractive index, or the presence of larger particles. Every size is counted with equal sensitivity.
NTA sensitivity limitation demonstrated experimentally. Reproduce the experiment yourself →
Quality Attribute 03 & 04
Subpopulation analysis and multicolor EV phenotyping
The challenge
EV preparations are heterogeneous mixtures. Distinguishing the subpopulation of interest by surface phenotype or cargo requires single-particle resolution — something bulk assays and light-scattering methods cannot provide.
With the ARC
The ARC measures size, concentration, and up to 3 fluorescence channels simultaneously for every particle. Fluorescence-positive subpopulations are quantified in absolute units alongside the full distribution — no separate instrument, no separate run.
Example result
Fluorescent EVs detected at 1 × 10&sup9; particles/mL — representing 8% of all particles in the 80–150 nm range.
Total concentration in range: 1.3 × 10¹° particles/mL
Full characterization data: VesiRef CD63 GFP App Note (PDF) →
Subpopulation analysis: fluorescence-positive particles quantified as a fraction of the total size distribution.
Multicolor phenotyping of VesiRef CD63 GFP EVs (Vesiculab, UK): simultaneous size, concentration, and per-particle GFP and CD63 fluorescence.
Method Comparison
How F-MRPS and MRPS compare for EV characterization
When experimental control is on the line, you need more than light scattering alone. The comparison below covers the attributes that matter most for EV work.
Resources
EV application notes and technical guides
Ready to characterize your EV samples?
Submit a sample for a free measurement, or schedule a live demonstration with one of our applications scientists.