Fast MDx is a sample-to-results system with minimal user interaction.
A single system can generate up to 188 patient results per hour.
Once the sample is entered into the system and the patient barcode data is matched to the sample tube, the Fast MDx platform runs automatically.
The whole process can be viewed as essentially 4 processes:
Data and sample entry
Barcode scanning and pipetting performed by laboratory staff.
Sample preparation for qPCR
Fast MDx performs various dilution and liquid transfer steps to combine the sample with the direct qPCR assay.
The resulting mix is transferred to the microtiter xxplate™ and a heat seal is applied to ensure that sample integrity is maintained throughout the qPCR run. This step takes around 5 minutes for the 94 samples.
qPCR thermal cycling
Ultra-fast qPCR run is performed using resistive heating technology and takes around 25 minutes to report results.
Reporting of results matched to patient data
Results are exported directly to the patient record (hospital situation) and a printout generated to report the result to the clinician requiring the non-laboratory test eg border authorities at an airport.
Fast MDx employs the proven technologies developed by BJS and used internationally in the xxpress® NGx thermocycler
Dual heater block technology
The microtiter xxplate shuttles between 2 blocks that at are at different temperatures.
Fluorescence measurements are taken on the fly after the extension and annealing step using LED excitation and photodiodes to very quickly capture the fluorescence measurement from each well in turn, thus eliminating crosstalk.
Diagrammatic representation of a cross section through the xxplate ® showing the intimate relationship between the plate and sample temperatures.
Cooling of the consumable is by means of several individually controlled air jets giving multi-zone control of cooling too.
Temperature measurements are made using thermocouples attached to each heater block.
The platforms maintains thermal accuracy and uniformity of ± 0.3°C.
LED excitation channels and photodiode emission reading channels
| Channel | Excitation (nm) |
Emission (nm) |
Common dyes |
|---|---|---|---|
| 1. Green | 474 | 507-527 | FAM/SYBR Green |
| 2. Yellow | 535 | 567-583 | JOE/HEX/VIC/TA |
| 3. Amber | 578 | 617-633 | ROX/Texas Red |
| 4. Red | 635 | 667-679 | Cy 5 |
| 5. Deep Red | 662 | 698-724 | Cy 5.5 |
The LEDs excite the fluorophores with a narrow band excitation wavelength this minimises cross talk and ensures the maximum signal is generated even from low abundance Nucleic Acid samples.
Photodiodes read the emitted light which is strictly controlled through narrow band width filters.