Hand-held pipette with disposable capillary

In a pipette having a body carrying a plunger assembly including a plunger shaft for manual stroking in a liquid pick-up and dispensing mode to one stroke-end at a first stop, a plunger tip holding collet on the plunger assembly, a body extender connected to the body and having a capillary receiving end near said collet, an improved disposable capillary and plunger tip assembly comprising (a) a capillary having a precision molded internal bore, an internal peripheral shoulder adjacent that bore at one end of the capillary, a flange carrying a beveled seating face at the other end of the capillary for releasable mounting upon the receiving end of said body extender;

• and (b) a plunger tip having a head at one end for reciprocation within the precision molded bore of the capillary and a rod shaped end for insertion in said collet.

In a pipette having a body carrying a plunger assembly for manual stroking in a liquid pick-up and dispense mode, a body extender connecting the body and having a capillary receiving end surrounding an internal bore, the improvement comprising

• a beveled seat around said bore at the receiving end of said body extender;
• a capillary having a flanged end with a beveled seating face corresponding to said beveled seat of the body extender;
• and a canted annular spring secured within an annular groove at the end of said body extender to hold the seating face of the capillary flange against the seat of said body extender.

A disposable capillary and plunger tip assembly for a pipette including (a) a capillary having a precision molded internal bore and a parking place bore adjacent that precision molded bore which has a diameter larger than the precision molded bore;

• and (b) a plunger tip having a head for reciprocation within the precision molded bore of the capillary which is of a diameter larger than the precision molded bore but smaller than the parking place bore.