Microfluidic devices for high throughput screening of cell-cell interactions

A method for encapsulating two cells in a single droplet, the method comprising:

• flowing a first aqueous phase comprising a first ordered stream of cells in a first microchannel towards a junction, the first microchannel comprising a first curved region that comprises between 60 to 120 undulating portions, wherein an undulating portion of the first curved region comprises at least a 45 degree change in a flow vector across a length of the undulating portion.
• flowing a second aqueous phase comprising a second ordered stream of cells in a second microchannel towards the junction, the second microchannel comprising a second curved region that comprises between 60 to 120 undulating portions, wherein an undulating portion of the second curved region comprises at least a 45 degree change in a flow vector across a length of the undulating portion;
• flowing an oil phase in a third microchannel towards the junction;
• and
• at the junction, generating the single droplet formed from the first aqueous phase, the second aqueous phase, and the oil phase, the single droplet comprising a cell from the first ordered stream of cells and a cell from the second ordered stream of cells.