Liquid sample dispensing methods for precisely delivering liquids without crossover

Abstract

A method for reducing carryover of and delivering liquid taken from a source container by a dispensing means to a target container by spinning the target container so that any liquid within the target container is removed from the dispensing means prior to dispensing liquid into the target container.

Description

FIELD OF THE INVENTION[0001]The present invention relates to liquid sample dispensing in which a sampling pipette aspirates liquids from a sample or reagent container and dispenses the aspirated liquid into a reaction vessel. More particularly, the invention relates to a system for precisely delivering an amount of liquid from a sample or reagent container into a reaction tube and for reducing carry-over of liquid from one reaction tube to the next, thereby protecting the integrity of the solution within the reaction tube.BACKGROUND OF THE INVENTION[0002]Various types of tests related to patient diagnosis and therapy can be performed by analysis of a sample of a patient's infections, bodily fluids or abscesses. Such samples are typically placed in sample vials, extracted from the vials, combined with various reagents in special reaction vessels or tubes, incubated, and analyzed to aid in treatment of the patient. Automated clinical analyzers adapted to perform these operations typic...

AI Technical Summary

Benefits of technology

The invention provides a method for using a sampling pipette that reduces carryover between samples and delivers liquid accurately from a source container to a target container. The method involves spinning the target container to move any liquid away from the pipette, minimizing carryover. The pipette can dispense a droplet of liquid into the target container, and the method allows for a second droplet to be dispensed by spinning the target container again. This ensures that the amount of liquid dispensed is controlled and limited to the original aspirated volume. Overall, the invention provides a reliable and efficient method for delivering liquid samples.

Problems solved by technology

Conventional pipettes suffer the disadvantage that liquid tends to remain on the exterior surface of the pipette when the pipette is withdrawn after aspiration.

In either case, the volume of liquid received by the vessel is altered in an unpredictable fashion.

Another disadvantage is that reusable probes used to deliver liquid aliquots from successive containers such as tubes or liquid reagent vessels are a source of intra-sample carryover or contamination.

However, disposable pipettes are costly and over a long period of time, become an unexpectedly high item of unwanted expense.

However, wiping is an extra potential source of contamination, and also introduces additional automated mechanisms that lower the throughput rate and increase the expense of an analyzer.

Wash chambers can leak fluid and also can channel along only one side or a portion of the pipette which can leave residue on the pipette exterior.

Additionally, if a last drop of wash diluent does not drop off the pipette and is carried back to an aspiration vessel, the droplets dilute the sample or reagent, introducing unwanted sources of error.

Such aspiration, however, introduces the possibility of drawing the unwanted carry-over contaminants deeper into the tubing and apparatus which comprises the sampling system.

From this discussion of the art state in automated microbiological analyzers, it may be seen that while there has been considerable effort made toward the problem associated with minimizing contamination and carry-over between samples, there remains an unmet need for a simplified system to address the related problems of precisely delivering an amount of liquid from a sample or reagent container to a reaction tube and for reducing carry-over of liquid from one reaction tube to the next.

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