Plasma separating microfluidic device

A method of preparing and transporting a sample from whole blood comprising the steps of:

• (i) arranging in a microfluidic device, a substantially flat porous membrane so that a lower surface of the porous membrane forms an intersection in an acute angle with a hydrophilic surface of a support structure, wherein said porous membrane extends diagonally between a channel bottom and a channel cover of a capillary channel configured to receive and accommodate a lateral capillary flow, wherein a portion of the lower surface of the porous membrane contacts a top of the channel cover;
• (ii) applying at least 30 μl whole blood to an upper surface of the membrane and admitting separation of plasma through the membrane;
• (iii) admitting a wedge-shaped space between the membrane and the support structure to be gradually filled with separated plasma;
• and
• (iv) filling the capillary channel in fluid communication with said wedge-shaped space and metering a defined volume of separated plasma.