Thermal cycler
A thermal cycler or thermal cycler , also known as a PCR block , is a device that is able to independently carry out the temperature cycles of a polymerase chain reaction (PCR).
Structure and functionality
A typical PCR cycle consisting of a denaturation step followed by the primer hybridization (engl. Primer annealing ) and elongation . This cycle is usually run through about 20–45 times in a PCR run. The reaction solutions (PCR batches with volumes between 5 and 100 µl) are often carried out in small micro-reaction vessels . In the past, mineral oil was layered over the test approaches to prevent evaporation; nowadays the problem is largely solved by lids that can be heated up to 100 ° C. The thermal cycler enables fully automated execution of various temperature-dependent reactions (PCR, restriction reactions , ligation steps , and much more). For some applications, such as Real Time Quantitative PCR, there are special thermal cyclers that are equipped with optical systems for fluorescence excitation and fluorescence measurement. The integration of the device in so-called high throughput experiments for analyzing large numbers of samples in “robot streets” (e.g. in the context of drug analysis) is already widespread. High process rates with small sample quantities can also be achieved with the help of chip thermal cyclers . Flow-through thermal cyclers allow the rapid serial processing of larger sample series in the nanoliter range, which is particularly interesting for miniaturized DNA analysis systems.
Thermal cycler "Baby Blue", approx. 1986
Thermal cycler
Modern thermal cycler
Display of the control element, status display of the running PCR program
opened thermal cycler, heating block with eight PCR reaction tubes
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literature
- Friedrich Lottspeich , Joachim W. Engels, Solodkoff Zettlmeier Lay: Bioanalytik . Spectrum, Heidelberg, 3rd edition 2012, ISBN 978-3827400413 .
