Patent ID: 8551787

Claim:
A microfluidic method for carrying out sequential binary reactions in a microfluidic device, said microfluidic device comprising a plurality of unit cells, wherein each unit cell comprises a flow passage network comprising flow channels and chambers, said network comprising first, second, third, fourth and fifth flow portions, a first valve disposed between the first and second portions, a second valve disposed between the second and third portions, a third valve disposed between the third and fourth portions, and a fourth valve disposed between the third and fifth portions; wherein the volume of the fifth portion is greater than the volume of the third portion, said method comprising: a) with the first valve closed, introducing a first solution M into the first portion; b) with the first and second valves closed, introducing a second solution N into the second portion; c) after Steps (a) and (b), opening the first and second valves, and with the third and fourth valves closed, flowing solution M into said second portion thereby displacing at least a portion of solution N into said third portion, and flowing at least a portion of solution M into said third portion; whereupon the solutions M and N are mixed in the third portion thereby producing solution MN; d) with the third valve closed, introducing a third solution 0 into the fourth portion; e) after Step (c), closing the second valve; and f) after Steps (d) and (e), with the third and fourth valves open, flowing solution O into said third portion, thereby displacing at least a portion of solution MN into said fifth portion, and flowing at least a portion of solution O into said fifth portion; whereupon the solutions MN and O are mixed in the fifth portion thereby producing solution MNO.