Water in Fluorocarbon Oil Emulsions
Water in fluorocarbon oil emulsions (W/FO) are widely used in R&D environments primarily to achieve compartmentalization of biological samples within droplets and prevent egress of the material to the surrounding media such as Drop-Seq and RNA-Seq. Of particular importance is the ability to produce high-quality, monodisperse droplets and the ability to do so reproducibly and at a high production rate.
The combination of Fluigent pressure pump units and Raydrop microfluidic devices developed and manufactured by Secoya enable smooth fluid delivery, precision flowrate control, automation, and reproducibility necessary to generate high-quality water in fluorocarbon oil emulsions.
Materials and methods
Reagents
Droplet Phase: Water (Mili Q)
Continuous phase: dSurf
| Reagent | Supplier | Catalogue number | CAS Number |
| Water | Ultrapure 18.2 MΩ – cm | – | 7732-18-5 |
| dSURF | Fluigent | DR-RE-SU-12 | – |
Microfluidic Setup
The microfluidic setup was composed of:
Protocols steps
Results
| Continuous phase flowrate (μl/min) | Droplet phase flowrate (μl/min) | Droplet diameter (μm) | Production rate (Hz) |
| 100 | 5 | 63 | 636 |
| 100 | 10 | 67 | 1058 |
| 100 | 15 | 71 | 1334 |
| 50 | 5 | 68 | 506 |
| 50 | 10 | 73 | 818 |
| 50 | 15 | 76 | 1087 |
| 25 | 5 | 72 | 426 |
| 25 | 10 | 75 | 754 |
| 25 | 15 | 81 | 898 |
| 15 | 15 | 85 | 777 |
Conclusion
Fluigent pressure-based flow controller units and Raydrop microfluidic device were successfully used to generate high-quality, monodisperse droplets of water in fluorocarbon oil. The droplet size was controlled in the range of 63 – 85 μm by adjusting the continuous and dispersed phase flowrates. Peak stable droplet production rate was recorded for 71 μm droplets at 1334 Hz. The production techniques developed here can use a wide range of compartmentalization applications such as Drop-Seq and RNA-Seq