Pipette tip and mounting shaft with rear venting feature

A disposable pipette tip for a pipette system comprising a disposable pipette tip and a tip mounting shaft, the tip mounting shaft having an upper locking section having a stop and a lower sealing area located below the stop, and a shaft head contiguous with the lower sealing area, wherein the lower sealing area provides a circumferential sealing surface, and the shaft head comprises one or more of grooves formed therein, the disposable pipette tip comprising:

• a barrel having a lower opening through which liquid is aspirated into the barrel and dispensed from the barrel, wherein the diameter of the lower opening is less than the diameter of the barrel at an upper end of the barrel;
• a collar having a continuous inner surface with a circular circumference in its relaxed state, an upper opening for receiving the tip mounting shaft, and a lower end with an inside diameter that is larger than an inside diameter of the upper end of the barrel;
• a circumferential stabilization ring encircling the inside surface of the barrel and extending inward from the inside surface of the barrel;
• an upper locking and stabilization ring extending inward from the continuous inner surface of the collar, wherein the upper locking and stabilization ring is configured to engage a plurality of outwardly extending lobes on the upper locking section of the tip mounting shaft;
• a circumferential tip shoulder connecting the lower end of the collar to the upper end of the barrel;
• and
• means for sealing against the lower sealing area proximate the one or more grooves on the mounting shaft below the stop on the mounting shaft;
• wherein the one or more grooves are configured to permit a flow of air to enter into the pipette tip barrel through the upper opening in the collar during an ejection process of the pipette system, wherein the circumferential stabilization ring is located below said sealing means for sealing the disposable pipette tip.