Pipettor and externally sealed pipette tip

A pipettor, comprising:

• a pipettor support;
• a chassis, said chassis coupled to said pipettor support, said chassis moveable with respect to said pipettor support;
• a vertical displacement motor coupled to said pipettor support and said chassis, said vertical displacement motor moving said chassis with respect to said pipettor support;
• a pipette block coupled to said chassis, said pipette block defining a plurality of pipette bores being machined into said pipette block and adapted to slidably receive pipette tips, said pipette bores having an open end and a closed end;
• a pipette block motor coupled to said pipette block, said pipette motor moving said pipette block relative to said chassis;
• a locking plate assembly being fixed to said chassis, said pipette block moving vertically with respect to said locking plate assembly, said locking plate assembly adapted to receive pipette tips and to releasably lock pipette tips into place relative to said locking plate so that said pipette block may be moved relative to said locking plate to aspirate and expel fluid by pipette tips, said locking plate assembly including a first stationary plate, a second stationary plate, and a locking plate slidably operating between said first and second stationary plates;
• said first stationary plate defining first pipette apertures adapted to receive pipette tips, said first stationary plate defining locking-flange receiving notches adapted to receive a locking flange of a pipette tip, said receiving notches proximate said first pipette apertures;
• said locking plate defining pipette locking slots adapted to receive pipette tips, said pipette locking slots generally aligned with said first pipette apertures, said locking plate moving relative to said first and second stationary plates to lock and unlock pipette tips with respect to said locking plate assembly, said locking plate defining pipette locking slots having a wider first end and a narrower second end such that a pipette tip with a locking flange is able to pass through said first end including said locking flange but is unable to pass through said second end as being stopped by said locking flange obstructed by said locking plate;
• a second stationary plate defining second pipette apertures adapted to receive pipette tips, said second pipette apertures generally aligned with said first pipette apertures such that pipette tips may pass through said first pipette apertures, said pipette locking slots, and said second pipette apertures enabling said locking plate assembly to engage and disengage pipette tips;
• and
• a locking motor coupled to said chassis and said locking plate assembly, said locking motor controlling said locking plate assembly to releasably lock pipette tips into place;
• whereby
• said pipette block is moved relative to said chassis and said locking plate assembly to aspirate and expel fluid by pipette tips.

A pipette tip having an open proximal end and a tapered distal end, comprising:

• first and second external and spaced-apart taps coupled to an exterior of the pipette tip adjacent the open proximal end, said first and second external taps adapted for engagement with a pipette tip holder such that said first and second taps serve to align the pipette tip with a pipette tip holder when the pipette tip is externally engaged about said open proximal end by said pipette tip holder;
• a seal, said seal disposed below said first and second taps, said seal circumscribing the pipette tip and adapted to engage an interior of said pipette tip holder such that said seal seals the open proximal end of the pipette tip and inhibits fluid flow past said seal to urge said fluid flow only through the pipette tip and not past said seal;
• and
• a locking flange coupled to the pipette tip, said locking flange circumscribing the pipette tip in a spaced-apart relationship from both the open proximal end and the tapered distal end.