Patent ID: 6973845

Claim:
A pipette mandrel for engagement with the interior wall of a pipette tip, the pipette mandrel comprising: a. an elongated hollow structure, the hollow structure including a proximate end and a distal end; b. a lead-in portion formed on the distal end of the hollow structure; c. a first cylindrical portion adjacent to the lead-in portion, the first cylindrical portion having a first exterior diameter, d. a second cylindrical portion adjacent to the first cylindrical portion, the second cylindrical portion having a second exterior diameter that is greater than the first exterior diameter; e. a first non-resilient raised band positioned upon the first cylindrical portion, the first raised band having a diameter greater that the first exterior diameter of the first cylindrical portion, the first raised band for contacting the interior wall of the pipette tip to form a first seal between the first raised band and the pipette tip; and f. a second raised band positioned upon the second cylindrical portion, the second raised band having a diameter greater that the second exterior diameter of the second cylindrical portion, the second raised band for contacting the interior wall of the pipette tip to form a second seal between the second raised band and the pipette tip.