What is droplet-based microfluidics ?
Droplet-based microfluidics comes from microfluidics in which handling fluids at the microscale leads to droplets production and manipulation.
This technology is an emerging and powerful tool for biotechnological analyses as digital polymerase chain reaction (dPCR) or single cell analysis.Droplets, which behave as microreactors, are formed in microfluidic chips, creating a considerable increase in the number of experiments in a reduced time.In order to stabilize aqueous droplets in fluorinated oil in the scale of experiments, fluorinated surfactants are used.
Our formulations are specially designed to use it in different fields like :
- DNA amplification (dPCR)
- Single cell analysis
- Enzyme or protein screening
- Isolation of bacteria
Droplet surfactant APPLICATIONS
For dPCR applications
Polymerase Chain Reaction (PCR) is a technique that allows one to make multiple duplicates of a DNA or RNA sample (up to several tens of thousands). By artificially increasing the amount of samples, it simplifies the identification of targeted sequences in the samples.
Scientists developed probes to detect these sequences amidst the whole sample but they could not detect sequences present at under 10%. Droplet-based microfluidics allowed for huge improvements of this technology. With drople-based microfluidics it is now possible to detect sequences present at under 0,01%.
There are numerous applications that can benefit from this improvement starting from mutation detection in research to cancer monitoring in hospitals. This major improvement can only be achieved by using droplets that are stable through all the PCR workflow (usually 2 hours run and frequent changes of temperature up to 95°C) and that is what our surfactants are made for. Its unique features allow them to keep emulsions stables while preserving the precious samples encapsulated.
For screening applications
Droplets can be used to individually encapsulate elements (cells, proteins, molecules, etc.) in microfluidic chips and then test their response to certain environments. For that purpose, scientists have developed microfluidic tools based on two different features:
- Electrical fields : to slightly destabilize interfaces in order to either introduce new compounds once the droplets is formed or to move the droplets into the right path (eg. to sort active cells from inactive ones, like shown on the picture above).
- Fluorescence: probes are designed to emit very intense lights when a certain event is occurring in the droplets. This is what allows scientist to detect responses from the elements which they encapsulated.
In all of these cases, the key properties for the surfactant are :
- Maintaining the droplets’ integrity even when under electric fields and while allowing for the introduction ofnew compounds or manipulations,
- Keeping fluorescent dye inside the droplet to have an accurate measurement (to avoid leakage).
Our fomulations were designed to fulfil these criteria. As shown in the image, the droplets can be deformed and keep their integrity. And we have developed our products to significantly reduce the leakage which is one of the major issue that many researcher are facing.
For single-cell analysis
Poisson statistical law allows to predict the number of cells per droplets depending on the concentration in the sample and the intended droplet size.
The model can also be used to determine the concentration needed to get at most one cell per droplet.
Once the cells are individually encapsulated, it is possible to :
- Test their behaviour toward chemicals
- Sequence their genomes
- Study their proliferation
- …
These applications require a specific surfactant to obviously stabilize the droplets, but it also needs to be biocompatible so as not to interfere with the content of droplets, which is the case of ours products.