Drop-Seq Pack

Why use pressure for Droplet sequencing? 

While the original protocol was developed using syringe pumps, in the field of droplet sequencing, pressure-controlled systems have a few advantages. 

First, in terms of raw performance, pressure-driven systems are faster to set up, easier to control, and more stable over time, which allows for an emulsion of better quality: the droplet size will be more homogeneous, and start/stop populations will be smaller. This leads to better segregation of the cells, and less reagent use and less sample loss. Therefore, this allows for more efficient and optimal droplet sequencing. 

As the sample and beads need to be agitated throughout the experiment, it is usually done with a bulky stirring bar for syringe pumps. This leads to a dead volume that will not be injected into the chip. Pressure-driven setups can be run using more conventional containers that make it possible to use an external agitation system, such as a standard lab vortexing system. 

Using Fluigent Drop-Seq pack experiment with pressure controller allow then to: 

• Gain time: (less than 1 minute to obtain droplet compared to Macosko’s protocol, few minutes). 
• Avoid losing reagents (cells or beads) during transition time. 
• Have better control and avoid the problems that could appear with a syringe pump. For instance, using the droplet-sequencing pack prevents the backflow of the beads inside the cell’s channel which could drastically modify the experiment.