The benefits of no-clog microfluidics

by Annalisa Soldani, Friday, 10th June 2022

Thanks to a no-clog microfluidic design, kinetic studies can be performed under conditions that mimic the native environment as closely as possible, ensuring the raw data generated is a faithful depiction of kinetic activity.

What is it about?

As I mentioned this technology briefly in my previous post, Grating-Coupled Interferometry (GCI) is a method based on waveguide interferometry to monitor and characterize molecular interactions and to determine kinetic rate parameters, affinity constants and concentrations of analyte molecules interacting with an immobilized ligand.

Molecular interactions are detected as changes in refractive index within an evanescent field (orange) causing a phase shift of the beam in the waveguide, and hence a change in the interference to a reference beam projected in parallel to a screen.
Figure 1. Classical waveguide interferometry: Molecular interactions are detected as changes in refractive index within an evanescent field (orange) causing a phase shift of the beam in the waveguide, and hence a change in the interference to a reference beam projected in parallel to a screen.

Waveguide interferometry, like other optical label-free methods, measures changes in refractive index within an evanescent field near a sensor surface, which are caused by the displacement of buffer by analyte molecules binding to the ligand immobilized on the sensor surface. The refractive index changes occurring within the evanescent field of a waveguide result in a change of the light phase, which is read out interferometrically. In comparison to other optical label-free techniques such as surface plasmon resonance (SPR), the light travels throughout the waveguide, creating an evanescent wave that spans the entire length of the sensor surface. This allows more binding events to contribute to the overall signal, giving waveguide interferometry an intrinsically higher primary sensitivity for label-free interaction analysis (Figure 1).

Challenge

Label-free analysis of molecular interactions in complex biofluids such as serum provides valuable information to guide therapeutic antibody studies. However, these matrices often put surface-based biosensors under considerable stress as various components cause the microfluidics to clog. This can result in lengthy program delays while essential maintenance is performed.

No-clog technology

Thanks to our innovative, disposable microfluidics, the Creoptix® WAVEsystem is highly resistant to clogging. This makes kinetic analysis in physiologically relevant matrices possible, providing superior insight compared to traditional Surface Plasmon Resonance (SPR) technologies.

Creoptix® WAVEsystem offers robustness of crude samples normally only achieved with plate-based assays. Our innovative design of the patented microfluidic cartridge supports crude samples, pathogenic samples, harsh solvents and large particles of up to 1000 nm, enabling reliable kinetic analysis. This is made possible by the innovative fluidics design, which integrates all the microfluidics into the disposable cartridge (not within the device core) and places large bore standard valves downstream in the instrument instead of having microvalves near the chip (Figure 2). As a result, WAVEchips can also be exchanged within minutes for fresh microfluidics.

Section view of WAVEchip, showing microfluidics integrated into the disposable cartridge by placing the downstream valves instead of microvalves near the chip.
Figure 2. Section view of WAVEchip, showing microfluidics integrated into the disposable cartridge by placing the downstream valves instead of microvalves near the chip.

The non-clog technology renders the WAVEchips compatible with:

  • 100% serum, plasma and cell supernatant
  • Organic solvents, including high percentages of acetonitrile and dimethyl sulfoxide (DMSO)
  • Viscous detergents and additives to solubilize membrane proteins
  • Cell membrane preps, partially solubilized, unpurified material
  • Virus-like particles (VLPs), liposomes, or nanodiscs used as solubilization structures
  • Large binding partners: nanoparticles and crude membrane preps

To find out more about, join our webinar on June 29!

Further reading

About the author

After earning her Bachelor’s Degree in Commerce and Marketing, Bernadett entered the pharmaceutical industry to explore her passion for science and nature. During her time at Pfizer, she worked on various digital marketing projects and communication activities. Bernadett joined Creoptix in 2022 as a Marketing Communication Specialist, and is currently located in Zurich, Switzerland.

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