A mechanism that provides an improved method of loading and unloading a row of disposable pipette tips onto a handheld multichannel pipettor. A single button for tip load and unload operations is simpler than the current method of using a separate mechanism for ejecting the tips. The tips are configured in a rigid collar which is held by a clamp on the pipettor. An upward force combined with a sealing gasket that mates with the top of the pipette tips is used to provide the seal between the tips and the pipettor. This eliminates the requirement to “press downward” with excessive force in order to force the pipette tips onto a protruding sealing part. The loading and unloading of tips will be more reliable and repeatable, this providing better pipetting results. The low forces of the loading and unloading operations reduce the chance of repetitive stress injury for the operator.