Single Particle Interferometry
Score high resolution sizing of single lentivirus particles & EVs
What is Single Particle Interferometry?
Single particle interferometry is a label-free imaging technique that measures the size and composition of individual nanoparticles bound to a silicon-dioxide surface by analyzing interference patterns between scattered light and surface-reflected light. The method delivers nanometer-scale sizing on individual lentivirus particles, extracellular vesicles, and large viral particles in crude or purified samples, enabling titer measurements that discriminate intact particles from fragments and aggregates.
- Measures individual particles rather than bulk averages - each particle is counted and sized independently, enabling discrimination between intact particles, fragments, and aggregates within the same sample
- Detection reaches down to approximately 35 nm diameter, covering lentiviruses, extracellular vesicles, and many viral vectors
- Works in both crude and purified samples - complementary to bulk ensemble techniques like DLS and SLS, which report population averages rather than single-particle distributions
See the small stuff
In the world of biologics and gene therapy, when individual particles get too small to be seen by normal optical techniques, single particle interferometry is the go-to technique for one-by-one detection. Interferometry - specifically, interferometric reflectance imaging - is a unique way to measure mass or size of particles attached to a surface. When a particle latches on to a surface there is a change in how the light scattered by the particle interacts with light reflected from the surface - making interference patterns that tell you a lot about the particle. If you use interferometry when looking at individual particles, it gives you resolution down to the nanometer and can tell you a lot about gene therapy vectors - like lentivirus or exosomes.
Capture your targets
To get proteins and viruses to stay still, antibodies are used to capture target molecules at the surface of a silicon dioxide layer on top of a silicon layer.
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Light 'em up
A light source shines down on everything - and then gets reflected back up. The whole key to interferometry is that light scattered by a bound particle will interact with the light reflected by the surface, creating interference patterns that are dependent on the size and composition of the particle. Pick that up by a camera, and you can image particles one-by-one.
Make it real
If you know enough about your sample, you can translate these interference patterns into high resolution, single-particle size data on particles so tiny that they normally can't be seen.
Leprechaun
Leprechaun is the only system that hunts down viral titer by double-checking if particles are the right size and have the right structure - in crude or pure samples. Leprechaun's single particle interferometry uses the signal enhancing silicon dioxide surface of the Luni consumable to maximize interference of light reflected from the Luni surface and scattered by the captured virus. This results in high resolution sizing of single particles, down to 35 nm in diameter. Establishing viral size allows Leprechaun to separate viral fragments and aggregates from single lentiviral particles with all the parts.
Frequently Asked Questions
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Scientists now have the perfect solution for sizing lentiviruses with an instrument that sports super high resolution single particle interferometry. Have a question or ready to find out more?