A custom thermal cycler solution.
Fast and precise thermal cycling. Multiple parallel sample chambers in a single cartridge. A less-than-ideal thermal interface. Those were the challenges our team had to solve. And our solution needed to drive successful, reproducible PCR that supported the customer’s full point-of-care MDx instrument solution. We had to ensure results were accurate every time, all the time.
To accomplish these objectives, Plexus leveraged our experience with various thermal management and control applications. We analyzed the entire thermal cycler, including the cartridge system, and identified the critical considerations of the control system, the cartridge mechanism and the thermal interface. We tested and evaluated a variety of design options to determine which would best support the thermal cycling requirements for the customer’s application. Plexus chose the most reliable, consistent performing design to produce the required results, while balancing critical product lifecycle variables such as the cost of raw materials, development timeline, manufacturability, serviceability and component lifetime.
This completely custom system supports the customer’s consumable cartridge design, while leveraging TECs from trusted suppliers to enable scale and reliability.
Our design ensured the system can accurately, reliably and quickly:
- Minimize surface roughness anomalies of cartridges to improve thermal interface prior to sample analysis
- Accommodate gross cartridge curvatures and/or surface anomalies of 150µm in magnitude
- Dissipate heat to support the TEC’s ability to drive fastest possible thermal cycling between ambient and 95°C
- Ensure sample-to-sample thermal uniformity between cartridge chambers as well as unit-to-unit reproducibility
Our final design balanced the many requirements and tradeoffs to deliver thermal cycling capabilities with repeated cycling between typical high and low temperatures used in PCR. The Plexus solution provides uniform, repeatable results across the board — between cycles, PCR reaction chambers and relative to set points — and precise thermal cycling every time.