Spinning micropipette liquid emulsion generator for single cell whole genome amplification

Many on-chip approaches that use flow-focusingto pinch the continuous aqueous phase into droplets have become the most popular methods that provide monodisperse emulsiondroplets. However, not every lab can easily adapt a microfluidic workflow into their familiar protocols. We develop an off-chip approach, spinning micro- pipetteliquid emulsion(SiMPLE) generator, to produce highly stable monodisperse water-in-oil emulsionsusing a moving micropipette to disperse the aqueous phase in an oil-filled microcentrifuge tube. This method provides a simple way to produce picoliter-size droplets in situ with no dead volume during emulsification. With SiMPLE, single-cell emulsionwhole genome amplification was performed to demonstrate that this novel method can seamlessly be integrated with experimental operations and supplies that most researchers are familiar with. The SiMPLE generator has effectively lowered the technical difficulties in applications relying on emulsiondroplets.