System for nucleic acid based diagnostic assay

Abstract

An automated system is provided for carrying out nucleic acid based assays on a plurality of liquid samples with little or no intervention by a human operator. The system includes at least one reaction station adapted to hold and apply controlled amounts of heat to a plurality of reaction devices in which the liquid samples are receivable. Each of the reaction devices includes a sample area for receiving a liquid sample, a reaction area into which the liquid sample is movable to carry out a nucleic acid decontamination or amplification reaction on the sample, and a pneumatic port for allowing air to be aspirated from and dispensed into the reaction device to move the sample between the sample area and the reaction area. A robotically controlled aspiration and dispensing head is adapted to move into contact with the pneumatic ports of the reaction devices, and to aspirate air from and dispense air into the pneumatic ports of the reaction devices in order to move the liquid samples between the sample and reaction areas of the reaction devices. A programmable control system is provided for causing the robotically controlled aspiration and dispensing head to move into contact with the pneumatic ports of the reaction devices, and to aspirate air from and dispense air into the reaction devices in order to cause the desired movement of the liquid samples within the reaction devices. The robotically controlled aspiration and dispensing head is also adapted to transfer the liquid samples to and from the reaction devices using disposable pipettes, and to introduce liquid reagents into the reacted samples after the samples have been transferred from the reaction devices to separate assay devices. A robotically controlled wash head is also provided to aspirate and dispense wash fluids and reagent fluids from the assay devices.