Table 3.

Comparison of FACS-based and microfluidics-based screening platforms.

FACS-Based	Microfluidics-Based
The utility of FACS assays is limited to fluorophores that remain inside or on the surface of cells	The utility of microfluidics is broadened to components that are secreted
Water-in-oil emulsions must be converted into a water-in-oil-in-water emulsion (double emulsion)	Water-in-oil emulsions can be sorted directly
Pre-formed droplets are difficult to manipulate (restricted range of assays)	Pre-formed droplets are easy to manipulate: they can be divided, fused, incubated, analyzed, sorted, broken up
Limited control over the reaction conditions in a droplet	Much greater control over the reaction conditions in a droplet
Lack of control over the droplet volume, leading to polydispersity	Good control over the droplet volume, highly monodisperse
Requires standard cell sorters	Requires specialized instrumentation
Sorting speed up to 20,000 droplets/s	Sorting speed up to 2000 droplets/s

FACS—fluorescence-assisted cell sorting.