Panther System Theory of Operations

The Panther System theory of operation is described here to establish the required workings of the system.

The system uses a Distributor to move MTUs between modules in the system. It also uses a dual arm air-based pipettor system to dispense samples and reagents in either the sample dispense slot or reagent load stations. Dispense pumps inject the required universal fluids such as wash, oil, auto-detect, and cleaning fluid. Rotary forced air incubators are used to control the critical assay temperatures. Detection is performed in a Luminometer for chemiluminescence. MTUs are introduced to the system every 5 minutes, which allows for one test per minute. Each MTUMulti-tube unit—Container used to process tests in the instrument. An MTU contains five separate reaction tubes. The MTU is moved through the instrument by the linear distributor and includes five tiplets for pipettiing to be used in the mag wash station. is then moved through a series of processing steps that varies depending upon the assay format. The system is capable of processing different assay formats based upon a high level input file that describes that assay processing steps that the system is required to perform.

APTIMA Assay Chemiluminescence Process

An MTU is picked from the MTU Input Queue and placed in the Sample Dispense Slot. TCRTarget capture reagent—An assay-specific reagent added as part of specimen pipetting. (that is kept in suspension by rotary mixing) is pipetted to the MTU tubes. A single disposable tip is used for dispensing TCR into all five reaction tubes within an MTU. Cooled sample is then dispensed to each tube using individual pipette tips. Each time sample is dispensed, the pipettor verifies that both TCR and sample has been dispensed accurately. The MTU is mixed in the Sample Mix Station and then moved to the Transition Incubator to begin the ramp. The MTU is transferred to the High Temperature Incubator for Target Capture. The MTU is then moved to the Transition Incubator allowing it to cool evenly and is then moved to the Chiller Ramp to cool completely before going into the Magnetic Parking slot where magnetic TCR beads are pre-captured to the sides of the MTU wall. Once the TCR beads are captured, the MTU is moved to the Mag Wash module to separate the captured target from the residual fluids. The MTU incorporates small disposable tiplets that mitigate against contamination. The Magnetic Wash goes through a process of injecting wash solution, mixing, capturing beads, and aspirating residual solution two times to remove sample and TCR reagent residues. A vacuum system is used for the aspiration to assure optimal airflow and minimize aerosols. An Oil Pump dispenses oil to minimize evaporation during the rest of the assay process.

The MTU is transferred to the Amp Load Station and the Amp reagent is pipetted to each tube and mixed. The MTU is then transferred back to the Transition Incubator to begin the ramp, then to the High Temperature Incubator for the primer anneal step, then to the Transition Incubator again to cool before enzyme addition. The MTU is transferred to the Amp Load Station for enzyme addition by the pipettor, mixed and transferred to the Amplification Incubator for amplification. Once amplification is complete, the MTU is moved to the HPAHybridization protection assay—The Hologic HPA technique uses a specific DNA probe, labeled with an acridinium ester detector molecule that emits a chemiluminescent signal. Load Station where probe reagent is dispensed by the pipettor into each tube of the MTU and mixed. The MTU then returns back to the High Temperature Incubator for hybridization. Once hybridized, the MTU is moved to the HPA Load Station for select addition by the pipettor and mixed. The MTU is then transferred back to the High Temperature Incubator for the selection process to leave only the active label intact. Following the selection process, the MTU moves to the Transition Incubator at 43.7 °C to cool down evenly, then to the Chiller Ramp module for additional cooling, and finally to the Luminometer module.

In the Luminometer, Auto-detect 1 & 2 reagents are injected by dispense pumps and light-off occurs. The chemiluminescence is detected by a sensitive photo¬multiplier tube (PMTPhotomultiplier tube) and reported in relative light units (RLUs).

The MTU is finally moved to the Output Queue where the Deactivation Buffer fluid is injected by a pump, the MTU is allowed to sit for 15 minutes to clean then the fluids are aspirated to waste by the vacuum system. MTUs and pipette tips and tiplets are all disposed of in a Solid Waste Container. The liquid waste is contained in a Liquid Waste Bottle.

An auto-focusing barcode reader is used to read sample barcodes in the Sample Bay.

The system maintains the sample to result positive ID tracking by barcode scanning the MTU prior to performing the sample transfer into each MTU tube. Various encoders and electro-mechanical flags are used to insure that the MTU as it is moved through the system is positively tracked and that the correct assay processing steps have been performed. As a final check the MTU is barcode scanned prior to the final kinetic data collection step to insure that the MTU that started the processing has completed all processing steps and the positive sample ID was maintained throughout the system processes.

The Reagent Bay also has a dedicated auto-focus barcode reader. This reader can read each of the four lanes. The Reagent Bay is cooled. When Reagent Racks are loaded into the bay, the barcode reader reads each bottle label to assure positive ID.

The universal fluid bottles are arranged in an A/B configuration. There are two of each bottle for Auto Detect 1, Auto Detect 2, oil, wash and DQ fluid. The bottles have barcode labels and RFID tags and the bottles are read as they are inserted in the Universal Bay. The universal fluids are sized for 1000 tests each, assuming only a few prime sequences. The system automatically switches between the A and B bottles based upon the number of calculated tests remaining in the each bottle.