Patent ID: 7371329

Claim:
A method for filtering particles from a fluid comprising the steps of: providing an analytical platform comprising: a substrate; an array of microstructures on the substrate; an application surface located opposite said substrate relative to said microstructures; and a plurality of microchannels defined respectively between adjacent ones of said microstructures, said plurality of microchannels each having a first width at a first distance from said substrate and a second width at a second distance from said substrate, said first distance being shorter than said second distance, said second width being a minimum width that is smaller than said first width in each microchannel, said minimum width being equal to or less than a minimum dimension of particles to be filtered out of a fluid; applying the fluid to said application surface; using capillary forces to make the fluid enter said plurality of microchannels through the respective minimum widths thereof, wherein the particles to be filtered out of said fluid are prevented from passing through the minimum widths of said plurality of microchannels; and using at least one of capillary forces, gravity forces, and centrifugal forces to spread the fluid that has passed through the minimum widths of said plurality of microchannels along said microchannels into areas of the analytical platform where no fluid to be filtered was applied to the application surface.