Liquid sample/reagent metering and delivery method

摘要

A method for sampling, metering and delivering precise microliter volume aliquots of a liquid blood sample to mixing and testing means of an electronic blood analysis system for analysis using a sampling and metering valve assembly in which is defined plural through fluid flow paths, one of the flow paths including a loop for metering and isolating a sample aliquot therein, the method comprising the steps of defining first and second dedicated passages within the valve assembly displaced one from the other and from the loop containing the isolated aliquot, introducing an inert gas to the loop to force the aliquot therein to said first dedicated passage at the displaced location thereof, placing the first and second dedicated passages in communicating relationship and introducing lyse reagent to the second dedicated passage to force the isolated aliquot from the first dedicated passage with the lyse reagent to a location exterior of the valve assembly without contaminating any flow paths which has been traversed by the liquid sample or a fluid other than the lyse reagent.