Patent ID: 7592185

Claim:
A method of metering and mixing a dose of a sample liquid with a diluent liquid, the method comprising; providing a pipette including: an elongated body having an outer surface and an interior wall, a portion of the interior wall defining an internal cavity open at a lower end of the body; the body defining an opening in an upper portion of the body, through which air can be drawn from the cavity to draw liquids into the cavity through the lower end of the body; wherein the portion of the interior wall defining the internal cavity also defines a pocket open to the internal cavity, the pocket radially extending into the portion of interior wall defining the internal cavity, the pocket sized and configured to collect and retain a metered dose of a liquid drawn into the cavity as the cavity is otherwise evacuated; drawing a sample liquid into the pipette to a level above the pocket such that the pocket collects a metered dose of the sample liquid; expelling the sample liquid from the pipette under conditions that enable retaining the collected, metered dose of the sample in the pocket by capillary force; and then drawing a volume of a diluent liquid into the pipette a sufficient distance to contact the retained dose of sample liquid, to induce diffusion and mixing of the diluent liquid with the dose of sample liquid.