Patent ID: 8053239

Claim:
A digital microfluidic based method for protein extraction by precipitation from heterogeneous mixtures, comprising the steps of: a) providing a digital microfluidic device having an array of actuating electrodes formed on a substrate surface, a coating having a hydrophobic working surface coating the substrate surface and array of actuating electrodes, an actuating electrode controller for exciting or de-exciting said actuating electrodes for translating liquid droplets over said hydrophobic working surface; b) dispensing one or more first sample droplets containing protein, onto one or more first positions on the hydrophobic working surface, and dispensing one or more second droplets containing a protein precipitant onto one or more second positions on the hydrophobic working surface; c) translating one or more first sample droplets with one or more second droplets to one or more corresponding designated protein extraction positions on the hydrophobic working surface such that said first and said second droplets mix to form one or more secondary droplets; d) incubating one or more secondary droplets at said one or more designated extraction positions to precipitate said protein contained in the one or more said first droplets onto the one or more said designated protein extraction positions to separate the precipitated protein from a supernatant above the precipitated protein; e) actuating one or more of said discrete electrodes associated with the one or more corresponding extraction positions to remove the one or more droplets containing the supernatant from the one or more corresponding extraction positions to leave behind the precipitated protein; f) dispensing one or more third droplets containing wash solution onto said hydrophobic working surface and translating said one or more third droplets to said one or more corresponding extraction positions to wash the precipitated protein; g) drying the precipitated protein at the one or more extraction positions; h) dispensing one or more fourth droplets containing resolubilization solution onto said hydrophobic working surface and translating said one or more fourth droplets to said one or more corresponding extraction positions to produce one or more droplets of resolubilized protein; and i) translating the one or more droplets of resolubilized protein to one or more collection points on said hydrophobic working surface and collecting the one or more droplets of resolubilized protein.