Patent ID: 8003062

Claim:
A microchannel for separating blood plasma comprising: a substrate body; a separation channel which is formed inside the substrate body and extended in parallel to a longitudinal direction of the substrate body from a first end to a second end opposite said first end; at least two, first and second communication ports, which are formed at said first end of the separation channel; first and second branch channels, which are formed inside the substrate body and communicate with the first and second communication ports, respectively; and a separator structure, which divides the separation channel horizontally said first end of the separation channel and which is extended from a position where the first and second branch channels start to branch to a middle position of the separation channel between said first end and said second end; wherein in a state where the substrate body is extended perpendicularly to a direction of gravitational force, a blood sample containing blood cells and plasma flows from said second end of the separation channel to said first end of the separation channel, the blood cells in the blood sample settle out before the blood sample reaches said first end of the separation channel; and wherein the blood cells, having settled out, are introduced into one branch channel located at a lower side of the direction of gravitational force among the first and second branch channels and a majority of the plasma is introduced into the other branch channel located at a higher side of the direction of gravitational force.