Pipettor and externally sealed pipette tip

A pipettor for pipetting fluids, comprising:

• a pipette block defining a first pipette block hole having an open end and a closed end, said pipette block defining a first circumscribing groove proximate said open hole end;
• a pipette tip slidably engaging said pipette block through said first pipette block hole;
• and
• a first seal seated in said first circumscribing groove, said first seal providing a sliding seal between said pipette tip and said pipette block;
• whereby
• said pipette tip may travel into and out of said first pipette block hole to control fluid flow into and out of said pipette tip without fluid travel between said pipette block and said pipette tip due to said first seal.

A pipette tip for use in a pipette block having a closed-end hole, comprising:

• an open proximal end defining a first circumscribing groove;
• and
• a seal seated in said first circumscribing groove;
• whereby
• the pipette tip may be used in conjunction with the pipette block with the pipette tip travelling into and out of the closed-end hole to control fluid flow into and out of the pipette tip without fluid travel between the pipette block and the pipette tip due to said first seal.

A pipette block for use in conjunction with a pipette tip, comprising:

• the pipette block defining a closed-end hole and defining a first circumscribing groove proximate an open end of said closed-end hole;
• and
• a seal seated in said first circumscribing groove;
• whereby
• the pipette tip may be used in conjunction with the pipette block with the pipette tip travelling into and out of the closed-end hole to control fluid flow into and out of the pipette tip without fluid travel between the pipette block and the pipette tip due to said first seal.