US Patent 7794664 Pipette tip

A pipette tip includes a main body having an upper end, a lower end and a sidewall extending between the two ends. A bore extends axially through the main body between the upper and lower ends. The lower end has a bottom surface in which is formed a central opening that communicates with the axial bore to allow the passage of fluid therethrough. The bottom surface is formed with at least one groove that may be concentrically disposed or spirally disposed about the central opening. The at least one groove acts to inhibit fluid passing through the central opening from at least partially flowing along the outer surface of the sidewall from the central opening toward the upper end of the main body of the pipette tip.