Patent ID: 7695687

Claim:
A capillary system for controlling a flow of fluid, said capillary system comprising: at least one loading site, at least one flow channel having at least one test site, and at least one capillary pump controlling a flow rate of fluid in the flow channel, characterized in that said capillary pump comprises: open-ended side channels; at least two different zones with different capillary pressures; wherein the at least two different zones of the capillary pump are distributed along a central delivery channel with a large dimension providing low capillary pressure such that the side channels are filled preferentially, wherein said central delivery channel comprises posts in a middle of the central delivery channel for guiding the fluid into the side-channels; and wherein a cross-section of the side-channel is reduced at an end of said channel such as to form a capillary retention valve and retain the fluid within the side channel.