A thermocycler is a laboratory equipment also called a thermal sequencer. This equipment allows to obtain the amplification of DNA molecules by PCR (Polymerase Chain Reaction) technique, through cyclical changes of temperatures that generate in turn the amplification of strands of this nucleic acid.

This instrument is used for qualitative amplifications or even to quantify the amount of amplified DNA. PCR enables a small amount of DNA molecules to be amplified many times, exponentially. The PCR technique is an automatic process and can be completed in just a few hours. This process is carried out completely in a thermocycler, which is programmed to change the reaction temperature every few minutes making possible the denaturation and synthesis of DNA.

Characteristics of a thermocycler

A thermocycler is usually an electrical resistance block that distributes a homogeneous temperature (between 4°C and 96°C) through a plate for a programmable time. In some equipment, the electrical resistance has been replaced by Peltier (semiconductor) technology, which allows greater homogeneity in temperature.

Note that the thermocycler used in the endpoint PCR is not the same as the one used for a real-time PCR because the latter must detect fluorescence and in different absorption channels.

Operation of a thermocycler

The operation of a thermocycler is based on the realization of three important steps during the denaturing, alignment and extension PCR technique. This instrument heats or cools the tubes at three different temperatures, which are repeated over and over again (known as reaction cycles), the first being at 95°C (denaturation) during which the double strands of DNA are opened or denatured, remaining in the form of single strands; The thermocycler then adjusts the temperature in a range between 40 °C and 60 °C (alignment), at this temperature the hydrogen bridges between the oligonucleotides and DNA are constantly generated and broken, and those more stable junctions (those that are complementary) will last longer, leaving the oligonucleotides “aligned” forming a small double chain region. The polymerase binds to this small piece of double-stranded DNA.)

The polymerase binds to this small piece of double-stranded DNA and starts copying in a 5’ to 3’ direction; by adding a few more bases, the hydrogen bridges that form between the bases further stabilize the bond and the oligonucleotide remains at this site for the next step. The temperature then rises to 72 °C (a step known as an extension), since 72 °C is the temperature at which the polymerase reaches its maximum activity, and the synthesis of DNA fragments from oligonucleotides that had already been aligned continues. In the first cycle, with these three temperatures, the first fragments will form from genomic DNA. Then the three temperatures are repeated once again, but in this second cycle, the oligonucleotides, in addition to binding to the DNA we put in at the beginning, will also bind to the newly synthesized fragments of the first cycle, therefore, in this second step the polymerase will synthesize two long fragments copied directly from the DNA and two fragments of the expected size, which is the size between the two oligonucleotides we have used. This way with each cycle will increase the number of fragments the size we want.

Uses of thermocyclers

• End-point PCR allows the detection and control of DNA fragments of interest.
• In medicine, PCR is used as a diagnostic tool for either infectious diseases or inherited diseases.
• In paleontological studies, biological anthropology and forensic sciences.
• In evolutionary studies.

What do we offer you in Kalstein?

Kalstein is a company MANUFACTURER of laboratory equipment of the highest quality and that have the most advanced technology available at the best prices of the market, so we guarantee you a safe and effective purchase, knowing that you have the service and advice of a company specialized in the field.  This time we present you our Thermocycler YR01869, this new equipment has the following characteristics: HERE

• Comfortable and flexible module change
• The airtight seal protects TEs from consignment, maximizing their life.
• Two stage hot cover pressure regulator, supports good sealing performance
• Gold or silver module improves the efficiency of heat conduction
• Super High Definition Large, Color LCD Display.
• Intuitive and easy-to-use interface, makes programming quick and easy.
• Infinitely adjustable cover knob, suitable for various types of tube.
• Memory function in case of shutdown.
• Low noise, low power consumption, long service life.
• The heat cover can be placed at any angle to facilitate access to the sample.
• Metal material cover, more reliable and safe.
• You can link the hard disk and the mouse.
• Linked to PC for multiple control.

For more information we invite you to take a look at: HERE