Pipette cleaning methods and apparatus, neutralizing liquid vessels, and methods of reducing carryover

A method of reducing specimen carryover in an automated clinical analyzer, comprising:

• providing a pipette including a liquid backing;
• providing a neutralizing liquid vessel containing a neutralizing liquid in the automated clinical analyzer at a location accessible by the pipette;
• aspirating a first air segment into the pipette below the liquid backing;
• immersing the pipette in the neutralizing liquid;
• aspirating the neutralizing liquid into the pipette below the first air segment from the neutralizing liquid vessel;
• and
• following the aspiration, dispensing the neutralizing liquid back into the neutralizing liquid vessel.

An aspirating and dispensing apparatus, comprising:

• a robot;
• a pipette moveable by the robot, the pipette including a liquid backing;
• a pump fluidly coupled to the liquid backing;
• a neutralizing liquid vessel accessible by the pipette;
• and
• a controller configured to execute programmed instructions and generate control signals to move the robot and actuate the pump to effectuate:
• immersion of the pipette in the neutralizing liquid vessel to a desired depth;
• aspiration of a neutralizing liquid from the neutralizing liquid vessel into the pipette below the liquid backing;
• and
• dispensing of the neutralizing liquid back into the neutralizing liquid vessel.