Hybaid Limited is a UK biotechnology instrument and reagent company. It provides high quality instrument and reagent systems for molecular biology laboratories worldwide.
Hybaid has an extensive product range, including hybridisation ovens, Polymerase Chain Reaction (PCR) instrumentation, PCR reagents, and they are one of the world's leading manufacturers and suppliers of Thermal Cycling instrumentation.
(This section was paraphrased from the Hybaid website)
We were involved with Hybaid from April 1997 until August 1997.
We assisted Hybaid in the development of a new thermal cycler product, the PCR Express (see photo). The product was designed for laboratory use and had to pass the regulations associated with the European EMC and Low Voltage Directives.
- Extensive EMC testing required many modifications to be made to the original 8051-based controller circuitry, the switched-mode power supplies and the mains filters in order for the EMC profile of the product to fall within acceptable limits for a laboratory instrument. The primary problem area was a high power (500W) switched mode power supply. This was developed to provide a continuously variable drive for a number of Peltier effect devices, which allowed the aluminium sample block to be either heated or cooled below ambient temperature. A combination of mains filtering, screening and careful decoupling ensured that the conducted emissions were controlled. In-depth experience of the generic EMC specifications, EN50081 and EN50082, was obtained, together with practical experience of the application of the tests.
- Problems with sensitivity to electrostatic discharge were investigated.
The stringent requirements for immunity to ESD in the laboratory environment
meant that special precautions had to be taken in the design of the
instrument control panel.
- Product safety assessment resulted in several modifications being made to the control electronics and the switched-mode power supplies. The main safety issues involved the shielding of hazardous live parts and ensuring that the spillage of liquids presented no hazards to the operator. However, the ability of the instrument to heat a sample block to a high temperature required that the control electronics be designed for fail-safe operation in the event of either a sensor failure or a software failure. As a result of the work, the product was declared to be safe for laboratory use. In-depth experience of IEC1010 and EN55022 was obtained.
Thermal cyclers operate by altering the temperature of biological samples in a cyclic pattern over a period of time. With the correct reagents present in the sample tubes, and the correct temperature profile, the DNA of the samples multiplies. The chemistry involved is known as the Polymerase Chain Reaction, or PCR.
Important parameters in the design of thermal cyclers are:
- the precision with which the temperatures involved in the PCR reaction can be attained
- the speed at which the sample temperature can be changed
- the temperature stability, once the target temperature has been reached
- the temperature uniformity across the samples in a multi-sample system