Cooling for DNA Sequencing

DNA sequencing continues to be a growing tool in molecular biology, evolutionary biology, metagenomics, virology, medicine, food safety, and forensics.  This growth in the use and acceptance of DNA sequencing has been spurred on by the development of DNA sequencers that enable rapid result generation, speeding up the process, reducing the cost, and efficiently producing results for doctors, researchers, and forensic scientists.  The impact of DNA sequencing can be seen in medicine, where DNA testing is used to identify certain cancers and diseases.  Other medical applications include the sequencing of flu viruses such as coronavirus (SARS-CoV-2) that was sequenced from COVID-19 infected patients and has been used to develop both treatments and vaccines.

Several years ago Aspen Systems was approached by a leader in the industry to provide a chiller with sufficient cooling capacity for heat loads from computers, optics including lasers and cameras, and other electronic loads in a rapid DNA sequencing machine.  Multiple elements needed cooling within the confines of a tightly packaged piece of laboratory equipment.  With a cooling load of nearly 600 Watts, and a very tight temperature control requirement, this customer was interested in our miniature cooling systems capabilities.

Aspen Engineers engaged with the customer’s product development team to understand the requirements and constraints of the application.  In partnership with this customer, Aspen developed a custom liquid chiller subassembly with variable speed compressor and condenser fan, control PCB, wire harnesses, quick disconnect fittings, and an open frame sheet metal chassis for easy integration into their device.   To attain the tight temperature control, the customer directly reads the temperature of their critical device and controls the compressor and condenser fan speed through the use of a Proportional-Integral-Derivative (PID) controller.  By directly controlling the compressor speed, the tight temperature control was maintained at the customer’s device in a simple and effective manner.  To demonstrate reliability, Aspen built and operated five systems in accelerated life testing for nine months of continuous operation.  As is the case with many of our customers, after 5 years of continuous production, an upgraded chiller was developed with higher capacity for the next generation version of their DNA sequencer.