Similar to the natural replication process of DNA, its specificity depends on oligonucleotide primers complementary to both ends of the target sequence. PCR consists of three basic reaction steps: denaturation-annealing-extension: ①Denaturation of template DNA: After template DNA is heated to about 93 ℃ for a certain period of time, the template DNA is double-stranded or amplified by PCR The formed double-stranded DNA is dissociated to make it single-stranded, so that it can be combined with the primer to prepare for the next round of reaction; ② Annealing of template DNA and primer (renaturation): After template DNA is denatured into single-stranded by heating, the temperature When the temperature is lowered to about 55 ℃, the primer and the complementary sequence of the single-stranded DNA of the template are paired to bind; Based on the principle of base pairing and semi-retained replication, synthesizing a new semi-reserved replication strand complementary to the template DNA strand and repeating the cycle denaturation-annealing-extension three processes, you can obtain more "semi-reserved replication strands", and this This new chain can become a template for the next cycle. Each cycle takes 2 to 4 minutes and 2 to 3 hours to amplify the target gene to be amplified by several million times. Shanghai Haozhuang Instrument Co., Ltd. is a technologically innovative high-tech enterprise based in Shanghai and radiating the whole country. The company has first-class technical personnel and a good team of technicians, with advanced technology and strong development strength. Since the establishment of the company, the products and The service is recognized by customers and has a good reputation. The company adheres to the business philosophy of "integrity. Professionalism. Innovation. Growth" to provide customers with elaborate services. The company's main business and production scope include: testing instruments, laboratory equipment, cleaning equipment, environmental protection equipment and undertaking the design and customization of non-standard products and providing related technical services. mirrored clock,mirrored glass clock,mirrored clock round Hongsing Glass Hardware Porduct Co Ltd , https://www.hongsingglass.com
The PCR technology of Shanghai Haozhuang Instrument Co., Ltd. Haozhuang (LNB) brand gene amplification instrument PCR instrument illustrates that semi-reserved replication of DNA is an important way for biological evolution and passage. Double-stranded DNA can be denatured and melted into single strands under the action of various enzymes. With the participation of DNA polymerase and promoter, it can be duplicated into the same two-molecule shoulder shell according to the principle of base pairing. In the polymerase chain reaction experiment, it was found that DNA can also be denatured and melted at high temperature, and then renatured and double-stranded when the temperature is reduced. Therefore, through temperature changes to control DNA denaturation and renaturation, and design primers as promoters, adding DNA polymerase, dNTP can complete the replication of specific genes in vitro.
However, DNA polymerase will be inactivated at high temperature. Therefore, new DNA polymerase must be added every cycle, which is not only cumbersome to operate, but also expensive, which restricts the application and development of PCR technology. It was found that the thermostable DNA polymerase-Taq enzyme has a milestone significance for the application of PCR. The enzyme can tolerate high temperatures above 90 ° C without inactivation, and does not require enzyme addition per cycle, making PCR technology very simple At the same time, the cost has been greatly reduced, and the PCR technology has been widely used and gradually applied to the clinic.
Shanghai Haozhuang Instrument Co., Ltd. Hao Zhuang (LNB) brand gene amplification instrument PCR instrument working principle of PCR: