LabDisk for SAXS: a centrifugal microfluidic sample preparation platform for small-angle X-ray scattering.
Frank Schwemmer1, Clement E Blanchet2, Alessandro Spilotros2
1Laboratory for MEMS Applications, IMTEK - Department of Microsystems Engineering, University of Freiburg, Georges-Koehler-Allee 103, 79110 Freiburg, Germany. frank.schwemmer@imtek.de.
Lab on a Chip
|March 3, 2016
Summary
A novel centrifugal microfluidic LabDisk enables high-throughput protein structure analysis using small-angle X-ray scattering (SAXS) with minimal sample volume. This platform simplifies complex experiments, making advanced protein analysis accessible to non-experts at synchrotron beamlines.
Area of Science:
- Biophysics
- Structural Biology
- Analytical Chemistry
Background:
- Small-angle X-ray scattering (SAXS) is crucial for protein structure analysis.
- Current SAXS methods require significant sample volumes and complex preparation.
- There is a need for streamlined, low-volume sample handling for SAXS experiments.
Purpose of the Study:
- To develop and validate a centrifugal microfluidic LabDisk for automated sample preparation and analysis in SAXS.
- To reduce sample volume requirements and hands-on time for SAXS experiments.
- To enable routine high-throughput protein structure screening at synchrotron facilities.
Main Methods:
- A centrifugal microfluidic LabDisk designed for 120 different measurement conditions.
- Automated generation of 20 conditions per dilution matrix from three input liquids.
- Precise aliquoting of 40 nl volumes for five different SAXS-relevant liquids.
- On-disk fluidic operations including merging, mixing, and SAXS data acquisition.
- Application of the LabDisk for basic (radius of gyration) and advanced (ab initio 3D modeling) SAXS analyses.
Main Results:
- The LabDisk requires only 2.5 μl of protein solution, a tenfold reduction in sample volume.
- Preparation of 120 conditions takes less than 5 minutes of hands-on time.
- Demonstrated fluidic performance with low coefficient of variation (2.7-4.4%) for protein concentration.
- Successful application for determining radius of gyration and ab initio 3D model calculations.
- Analysis of glucose isomerase under varying conditions revealed concentration-dependent changes in radius of gyration.
Conclusions:
- The centrifugal microfluidic LabDisk significantly enhances efficiency and reduces sample requirements for SAXS.
- This platform simplifies SAXS experiments, making them accessible to non-experts.
- The LabDisk has the potential to revolutionize routine high-throughput protein structure analysis at synchrotron beamlines.
