Patent ID: 8460622

Claim:
A pipette tip dispensing device, comprising: (a) a housing configured to engage an outside perimeter of a loading block; (b) a distal barrier plate in connection with the housing; and (c) an array of nested pipette tip units, each of which nested pipette tip units is aligned with a channel in the distal barrier plate; whereby a one-layer pipette tip array is in the channels; which distal barrier plate comprises, a plurality of channels, each channels having a diameter larger than the widest portion of a pipette tip; two (2) or more different subsets of channels; a substantially flat top surface; and a substantially flat bottom surface comprising a plurality of tails around the channels; wherein: the tails around any one subset of channels are the same length; tails around a subset of channels have a length different than tails around another subset of channels; the of tails around each channel are configured to contact and deflect outwards against the proximal portion of a pipette tip when a pipette tip is dispensed and passes by the tails, thereby imparting a frictional force on the pipette tip when it is dispensed; and the plurality of tails around one subset of channels is configured to eject pipette tips through the one subset of channels at a time different than pipette tips are ejected through another subset of channels.