The increasing number of instruments makes life in the laboratory stressful. In addition to the monotonous and tiring manual steps needed to use them, instruments also generate noise and waste heat. Although heat can be reduced in an air-conditioned laboratory, increasing noise is a significant stress factor .
According to the recommendation of ISO 11690-1:1996(E) the noise emission and/or noise exposure should not exceed the following maximum values :
- In industrial workplaces: < 80 dB(A), (e.g. vacuum cleaner, noise at a busy street)
- For routine office work: < 55 dB(A), (e.g. normal conversation)
- For meeting rooms or tasks involving concentration: < 45 dB(A) (e.g. dishwashers, whispering)
One of the main sources of noise are the fans used in a PCR cycler to remove the heat from the Peltier elements. A second aspect is the air flow within the instrument, caused by the fans. The more the airflow is re-directed and strikes sharp edges or solid surfaces, the higher the caused noise level.
In general, you can differentiate between 3 states of the PCR cycler: idling, PCR run, and constant cooling at 4 °C.
The goal is a limit of 45 dB(A) whereas even 55 dB(A) can be a challenge for many PCR cyclers.
In the human sound perception, an increase in the sound power level by 10 dB(A) means a doubling of the loudness [3,4]. Thus, you perceive the maximal detected sound power level difference of e.g. 20 dB(A) as a 4-fold higher loudness on cycler 1 in comparison to cycler 2.
Power Consumption - Sustainability
Apart from noise pollution, the use of more laboratory instruments leads to higher power consumption in the laboratory. Often the instruments are continually in use, or they are kept in standby mode over long periods of time. Therefore, power consumption of laboratory instruments is subject to increasing scrutiny:
- Environmental protection – conservation of resources using energy efficient instruments,
- Increased demands on the electro-technical infrastructure in the laboratory.
In contrast to ULT freezers or heating ovens, a PCR instrument consumes a limited amount of power. Still, the differences between different PCR instruments can be enormous. Like ramp rate comparisons, a good way to compare power consumptions is to run the same PCR on different instruments and measure the power consumption.
1) Performance of a typical PCR program:
When analyzing in total 8 different PCR instruments, the following conditions with the same protocol (to reflect the use of the instruments during routine applications) where used.
60°C for 15 s (Cycle 30x)
The power consumption varied between 150 W and 470 W per run. All measurements were performed using an inserted 96-well PCR plate. The plate positions of columns 1, 3, 5, 8, 10, 12 were filled with 30 μL H2O each, which filled 48 of the 96 well positions.