Abstract: A continuous flow system is disclosed in which successive liquid segments are established containing different related components of a fluid package, such as an analysis mixture, separated by at least one immiscible segment, passed along a first section of a conduit, combined in a second section of the conduit and mixed while passing along a third section of the conduit, so as to provide a completely mixed segment. This system permits the delayed on-line mixing of different components of an analysis mixture, such as samples with reagents or diluents, as well as mixing and interaction of such components in a single conduit.

Abstract: New and improved connector is provided for the zero dead volume connection of separate, like diameter flexible tubing lengths by direct tubing length end abutment and connection under controlled conditions. The connector is particularly adapted for use with tubing lengths of fluorocarbon or like materials in contemporary biomedical sample liquid analysis systems which utilize an immiscible isolation liquid or "oil" to minimize sample liquid carryover and maximize the accuracy of sample liquid analysis results.

Abstract: Continuous flow metering apparatus and methods using liquid position sensors in conjunction with flow-stopping valves control (meter) fluid, e.g. sample/reagent/air, aspiration into a single conduit, such as in a continuous flow system. Air or other gas separates selected ones of the liquid segments. The volume of the aspirated segment is established by sensing a flow parameter of the segmented stream of a selected one of the sensors. A pulse is generated by the sensors (detectors), for example due to the change of light intensity at a liquidair interface traversing the conduit. The signal pulse from a sensor causes the actuation of a selected one of the valves and stops aspiration (flow) of the liquid by traversing the flow path in the conduit through an air segment. The valve cuts through air only. Therefore, the body of the valve does not contact reagent or sample liquid by this action and the risk of carryover contamination is avoided. With the aspiration cycle completed, the input end of the conduit, e.