Introduction
In 1971, PCR experiment method was published in the Journal of molecular biology, which for the first time accurately, refined and objectively explained the process of PCR experiment.
In 1976, the isolation of a thermostable DNA polymerase from Thermus aquaticus greatly increased the efficiency of PCR. While modern PCR technology is derived from a paper published in Science by Saiki and Mullis and others in 1988. PCR technology is an important cornerstone to support the development of modern molecular biology. The widespread application of this technology has spawned a huge market.
PCR technology is a molecular biology technique used to amplify specific DNA fragments. There are various kinds of machines designed for PCR technology such as PCR instrument, gradient PCR instrument, in-situ PCR Instrument, fluorescence quantitative PCR instrument (qPCR) and digital PCR instrument (dPCR), etc. The most frequently used are gradient PCR instruments and fluorescence quantitative PCR instruments. The manufacturers of PCR instruments are also numerous. ABI, Roche, Bio-Rad have high user acceptance.
Purchase suggestion
Precise temperature control system
For the PCR instrument, the temperature control index mainly refers to temperature accuracy, uniformity, and the temperature ramp rate.
Temperature accuracy: refers to the consistency of the sample hole temperature and the set temperature, which is directly related to the success or failure of the experiment. Since PCR is a process of geometric series amplification, whether denaturation, annealing or elongation requires accurate temperature control. Temperature control is particularly important for annealing temperature. A miss is as good as a mile. Therefore, temperature control means quality for PCR equipment. e.g.
Temperature uniformity: refers to the temperature difference between the sample wells, which is related to the consistency of the reaction results in different sample wells. Some users found that with the same sample and the same PCR reaction program, the final results were very different, perhaps because of the uneven temperature at different locations. At the same time, the position edge effect has a significant effect on the repeatability of PCR experiments. e.g.
Heating and cooling rate: faster heating and cooling speed can shorten the reaction time, and shorten the possible non-specific binding and reaction time, can improve the specificity of PCR reaction. e.g.
Enhanced features and functionality
Hot lid: The current PCR instrument is generally equipped with a hot cover, the temperature of the hot cover is set to 105 ℃ so that the temperature of the top of the sample tube reaches about 105 ℃, the evaporated reaction solution will not cause condensation on the tube cover and change the reaction volume. In this way, the user does not need to add paraffin oil to the reaction tube, and directly reduces the trouble of the subsequent reaction.
Sample holder: PCR reactions are mostly carried out in 0.2 or 0.5 tubes. Most PCR devices are also equipped with different replaceable sample slots to adapt to different sample tubes. The PCR instrument has two different sample wells of 0.2 and 0.5 in a tank. You can use two different reaction tubes or 96-well plates without changing the base, avoiding the trouble of changing the base.
Software: The new PCR devices all pay more attention to the simplicity of programming. The large screen, displaying real-time information, countdown, memory storage of multiple programs, automatic power-off protection, etc. are all helpful for the use of complex environments in the laboratory.
Hot lid temperature range: 20-110 ℃.
Conclusion
With the development of biotechnology, the PCR instrument has developed into a general laboratory instrument, and the PCR instrument operates in the laboratory for almost 24 hours. It is particularly important to buy a reliable instrument.
It is recommended that when purchasing a PCR instrument, in addition to temperature, function, and user-friendly design, it is also necessary to pay attention to price, service life, after-sales service, machine noise, brand awareness, etc.
