nir-vana innovation network

In bioanalytical applications, such as drug testing and screening, toxicity tests or single-cell sequencing, only small sample volumes are available. At the same time a large number of tests have to be performed under various experimental conditions, which is rather time consuming. Microfluidics chips offer the possibility to handle ultra-small samples in high throughput. The samples can be placed in individual droplets, which act as microreactors. Such microfluidic devices, which produce and handle individual droplets are already commercially available. The throughput is limited, though, by some essential processes such as the in-droplet enrichment, purification and separation of samples. Current methods of purification and separation focus on extracting the droplets into a secondary channel or adding functionalized micrometer-sized beads to capture them. These methods are either slow or require the sample to be processed off-chip, which sets a limit to high throughput processing.

The technology developed by the Swiss University avoids this problem. The invention introduces in-droplet electrophoresis for the direct manipulation of the sample. The droplets move at velocities over 10 mm/s perpendicular to an electric field - much like in free-flow electrophoresis (see figure 1. Schematic concept of a microfluidic device, comprising a droplet generator, a flow channel for electrophoretic enrichment and a Y-junction for droplet splitting). Charged biomolecules with different sizes and net charges separate into the upper and lower halves of the droplets. The flow characteristic within the moving droplets supports the separation and enrichment of charged analytes (see figure 2, Migration of charged molecules within the moving droplet without and with an applied electric field). The separation can be fine-tuned by changes in the ionic strength, pH and/or viscosity of the surrounding buffer. Typical electric fields are on the order of 200 - 400 V/cm. The electrodes are coated with a carbon-based composite material, which prevents bubble formation and other electrolytic by-products generation. Figure 3 shows a microfluidic chip with droplet generator, in-droplet electrophoresis (enrichment) and Y-junction (separation).
The invention includes a method for fast and low-cost fabrication and integration of such electrophoretic-based devices into microfluidic chips, which allows further processing of the enriched sample.

Potential product and market:
In-droplet electrophoresis is an add-on feature for microfluidic devices. These devices are used in the pharmaceutical industry for high throughput drug testing and screening.

Desired cooperation:
The Swiss university is looking for a licensing partner from industry who is already well situated in the microfluidic device market and would like to use this technology for increasing and optimizing their product portfolio.

Advantages & innovations

- Selective manipulation of biomolecules inside droplets without any additional intermediaries, such as beads. - Enrichment, separation, purification of biomolecules inside droplets on chip. - Rapid and sensitive separation of biomolecules. - High throughput, low-cost fabrication and operation.

Stage of development

Prototype available for demonstration

Partner sought

The specific area of activity of the partner: - producer of laboratory equipment - producer of microfluidic devices The tasks to be performed by the partner sought: - license the technology - integrate invention into commercially available microfluidic devices - produce and sell product