Patent ID: 7749737

Claim:
A method of analyzing a sample fluid comprising at least one nucleic acid molecule comprising a target sequence, and reagents for amplifying said target sequence, said method comprising the steps of: i) providing a device having a microfluidic fluid channel therein, said fluid channel having a plurality of valves associated therewith which when activated partition the fluid channel into a plurality of fluidically isolated reaction sites, wherein said fluidically isolated reaction sites are not located at junctions formed by the fluid channel and other channels that are in fluid communication with the fluid channel; ii) introducing the sample fluid into the fluid channel, wherein the sample fluid contains the target sequence in a concentration such that upon closing the valves to partition the fluid channel into a plurality of fluidically isolated reaction sites, thereby partitioning the sample fluid into a plurality of fluid portions, at least one fluid portion contains the target sequence and at least one fluid portion does not contain the target sequence; iii) closing the valves to partition the sample fluid into the said fluid portions; iv) amplifying the target sequence in said fluidically isolated reaction site(s) in which it is present; and v) determining the number of said fluidically isolated reaction site(s) that contain products of said amplification of said target sequence.