Patent ID: 6867049

Claim:
A method for obtaining a liquid sample having an increased cellular or particulate concentration for optical examination comprising: (a) providing an apparatus comprising: a separation chamber; a wall surrounding said separation chamber; a sample entrance; venting channels; a separation wall in said separation chamber, dividing said chamber into two compartments, said separation wall having at least one separation channel, whereby said at least one separation channel has the appropriate size and dimensions to allow undesired cellular or particulate species to pass through, while excluding larger desired cellular or particulate species from passing through; and a flow path in said separation chamber; (b) depositing a liquid sample into the sample entrance of said apparatus; (c) allowing the sample to flow into the separation chamber; (d) allowing the sample to flow along the flow path in said separation chamber; (e) allowing the sample to advance to the separation wall; (f) allowing the sample to advance through the separation wall and the at least one separation channel; (g) allowing the portion of the sample containing undesired cellular or particulate species to advance to the second compartment; (h) allowing the sample to advance to the end of the separation chamber; and (i) obtaining in the first compartment the sample having an increased cellular or particulate concentration, which has been prevented from passing through said separation channel(s).