Marlow Industries, Inc. Custom Thermal Cycler Blocks

Emerging micro-array and micro-fluidics biotech companies are turning to Marlow Industries to provide custom thermal cycler blocks for their life science and drug discovery instruments. While Marlow has a standard family of high-reliability thermal cycler (XLT) coolers, many companies lack the infrastructure to design and build a thermal cycler block assembly that will provide the desired performance. Marlow Industries provides a design and manufacturing service for those companies.

Standard (off-the-shelf) coolers may not necessarily provide the optimum solution. If this is the case, Marlow will provide a custom XLT cooler to assure that the requirements are met. This includes modification of standard XLT coolers in order to enhance their performance for a specific application.

The first step in designing a thermal cycler block is to model it using the latest computational fluid dynamics (CFD) software and then adjusting the design as necessary. Once a prototype has been built, its static and transient thermal uniformity is verified using thermal imaging. Thermal imaging (IR) has been a Marlow tool in the defense and photonics markets for over five years. Tight thermal uniformity across the sample area is extremely critical in temperature sensitive reactions. Typically the smaller the sweet spot (reaction area), the tighter the thermal uniformity can be maintained. Marlow thermal cycler block designs with a sweet spot of 3" by 3" (76.2mm by 76.2mm) and a thermal uniformity of +/-0.5°C have been achieved. However to assure that this uniformity is maintained in a system, the system must provide appropriate convection and radiation shielding.

The time required for a cycler to go through a complete thermal cycle is of critical importance to the end user because the faster the cycle, the quicker the end result. Cycling speed is usually noted in °C/sec for (1) heating and (2) cooling. In designing a thermal cycler block, a tradeoff exists between cycling speed and thermal uniformity. Given a fixed thermoelectric cooler design and power constraints, cycling speed is reduced as mass is added to improve thermal uniformity. However the design of the thermoelectric coolers and power applied are another important parameter in establishing both cycling speed and thermal uniformity. Transient times as high as 12 -15°C/sec can be achieved, although most current systems operate in the 3 –5°/sec range.

For more information or to discuss your needs, please send an email to medical@marlow.com or call Jerry Russell (214-342-4226) or Tim Floy (214-503-3378).