Quick wins for a faster PC:
Clear out junk files and repair common Windows errorsFree Scan →Fix the driver behind crashes, sound loss and screen glitchesFind Drivers →A self-resonant microhelix paired with a planar microcoupler enabled researchers to measure electron paramagnetic resonance (EPR) signals from very small protein crystals. In a 2019 study, the setup achieved up to a 28-fold signal-to-noise improvement over commercial EPR resonators and was demonstrated on crystals from two protein systems. That is the study’s maximum reported improvement, not a guaranteed gain for every sample or instrument.
Why are tiny protein crystals difficult to study with EPR?
EPR detects paramagnetic species by measuring how they respond to a magnetic field and microwave radiation. In protein research, those species can include enzyme intermediates and radicals. A conventional EPR resonator holds the sample in a microwave field, but a very small crystal may produce a signal too weak to measure efficiently in an ordinary arrangement.
As an Amazon Associate I earn from qualifying purchases.
Single-crystal EPR can reveal the orientation of a paramagnetic species’ magnetic properties relative to the crystal. That information can help researchers relate an enzyme intermediate to molecular structure and crystallographic data obtained from the same batch of microcrystals.
How does the self-resonant microhelix work?
Sidabras and colleagues combined a tightly wound, self-resonant microhelix with a planar microcoupler on a printed circuit board. The microcoupler transfers microwave energy to the helix, whose small geometry concentrates the microwave magnetic field around the crystal. This improves the resonator’s filling factor: the proportion of the resonator’s field interacting with the sample.
#1 Best Overall
- Lab equipment & instruments
- Made in united states
- Wilmad-LabGlass is a leading manufacturer of NMR and EPR sample tubes and accessories, a diverse line of Laboratory Glassware and Scientific Equipment, as well as Precision Engineered Glass, OEM Quartz components and assemblies. Our goal has always been to provide you with superior service, support and technical know-how. In addition, we offer select glass repair services to maximize the life of your laboratory items. Limited 90-day warranty included. Scientists rely on the expertise and artistic skills of Wilmad-LabGlass' engineers and glass specialists to manufacture NMR and EPR consumables and laboratory glassware of the highest quality. Used daily in academia, healthcare and chemical, petroleum and other industrial applications, Wilmad offers 7000+ items as part of their standard catalog as well as custom fabrication for individual glassware, glass repair services and OEM glass parts.
- 90-day limited warranty
The team implemented the assembly in a commercial X-band EPR spectrometer operating at 9.5 GHz. The paper describes measurements on protein crystals with volumes below 27 nL. Jason Sidabras described the helix to Chemistry World as “a lens for magnetic flux that is designed to maximise the filling factor for very small samples.”
How much more sensitive was the setup?
In the authors’ 2019 comparison with commercial EPR resonators, the microhelix setup produced up to a 28-fold improvement in signal-to-noise ratio. The figure is a measured maximum from that study; it is not a universal multiplier. Signal quality depends on experimental conditions, including the sample, its orientation, temperature and resonator arrangement.
Sidabras also told Chemistry World that experiments that had taken weeks could be performed in days. That is his reported comparison, not the primary paper’s measured sensitivity result or a general promise of shorter experiment times.
Recommended Free Tools
Which protein crystals did the researchers test?
[FeFe]-hydrogenase
The researchers measured single crystals of [FeFe]-hydrogenase from Clostridium pasteurianum (CpI), including the Hox state, and reported a proposed g-tensor orientation. The demonstrated crystal measured 0.3 × 0.1 × 0.1 mm.
Photosystem II
They also performed continuous-wave EPR on a photosystem II single crystal, measuring the YD radical at two orientations at 80 K. Together, these demonstrations show feasibility across two protein systems; they do not establish that every crystal type or EPR experiment will work equally well.
Independent reader supportYour contribution helps us test, update, and keep practical guides available for everyone.Can EPR and X-ray crystallography use the same microcrystals?
The approach makes it possible to study EPR signals in crystals small enough to be relevant to protein crystallography, helping researchers connect spectroscopic measurements with structural information. As Chemistry World reported, Dimitri Svistunenko of the University of Essex said the advance was promising because it could allow EPR data to be related to crystallographic data obtained on the same batch of microcrystals. EPR complements that structural work; it does not replace crystallography.
What the study does—and does not—establish
- Demonstrated: a microhelix-and-microcoupler assembly for X-band EPR on nanoliter-volume protein single crystals, with measurements on [FeFe]-hydrogenase and photosystem II.
- Reported performance: up to a 28-fold signal-to-noise improvement versus commercial EPR resonators under the study’s experimental conditions.
- Not established: a standard retail product, a specific purchasable model, routine adoption, or present-day market performance. The paper reports a specialized research apparatus, not a commercial accessory.
The primary paper, “Extending electron paramagnetic resonance to nanoliter volume protein single crystals using a self-resonant microhelix,” appeared in Science Advances in 2019. PubMed lists its publication date as 2019-10-04. The full paper includes the methods and results; its authors state that MATLAB code and data are available through the ACT-EPR project website.
Do these 3 things before closing this tab:
1Scan for outdated or missing drivers - takes under a minute2Clear out junk files and repair common Windows errors3Fix the driver behind crashes, sound loss and screen glitchesQuick Recap
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon at the time of purchase will apply.
