Pipette tip handling devices and methods

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.