Views: 7 Author: Site Editor Publish Time: 2021-11-16 Origin: Site
Gene amplification is the use of DNA polymerase to carry out specific chain replication, which is a commonly used technique at present. According to the purpose of DNA amplification and testing standards, gene thermal cycler can be divided into four categories: ordinary thermal cycler, gradient thermal cycler, in situ thermal cycler, and real-time thermal cycler.
Ordinary gene thermal cycler
Generally, a gene thermal cycler that can only run a specific annealing temperature for one PCR amplification is called a traditional gene amplification instrument, or an ordinary gene amplification instrument. If you want to do different annealing temperature, you need to run multiple times.
Ordinary gene thermal cycler is mainly for simple amplification of the annealing temperature of the target gene. It can be used in scientific research, teaching, clinical medicine, inspection and quarantine and other institutions.
Gradient gene thermal cycler
"One-time PCR amplification can set a series of different annealing temperature conditions (usually 12 temperature gradients) called gradient gene amplification instrument. Because the most suitable annealing temperature for different amplified DNA fragments is different, a series of gradient annealing temperatures are set for amplification, so that one-time PCR amplification can screen out the most suitable annealing temperature with high expression level for effective Amplification.
The gene cycler is mainly used to study the amplification of unknown DNA annealing temperature, which saves time and money. It can also be used as an ordinary gene thermal cycler without setting a gradient. A true gradient gene thermal cycler has precise heating and temperature control probes for each row of tubes. Other gene thermal cyclers are designed to control the temperature from the heat transfer between the two ends. At present, gradient gene thermal cyclers are mostly used in scientific research and teaching institutions.
In situ thermal cycler
In situ thermal cycler is an intracellular gene amplification instrument used to analyze the location of target DNA in the cell. Such as the location of the pathogenic gene in the cell or the location of the target gene in the cell. The integrity of cells or tissues can be maintained, so that the gene amplification reaction system can penetrate into the tissues and cells, and the gene amplification can be carried out at the location where the target DNA of the cell is located. Not only can the target DNA be detected, but also the position of the target sequence in the cell can be marked. It is of great practical value to study the pathogenesis, clinical process and pathological changes of diseases at the molecular and cellular levels.
Real-time thermal cycler
Real-time thermal cycler is based on the design of ordinary gene amplification instrument, adding fluorescence signal excitation and acquisition system and computer analysis and processing system, forming an instrument with fluorescence quantitative PCR function. The principle of PCR amplification is the same as that of ordinary PCR amplification. The primers added during PCR amplification are labeled with isotopes, fluorescein, etc., and the primers and fluorescent probes are used to specifically bind to the template at the same time for amplification. The results of the amplification are connected to the computer analysis and processing system through the real-time acquisition signal of the fluorescence signal acquisition system, and the quantified real-time result output is obtained.
Real-time thermal cycler has single-channel, dual-channel and multi-channel points. When only one type of fluorescent probe is used for labeling, a single channel is used; when there are multiple fluorescent labels, multiple channels are used. A single channel can also detect multi-fluorescence markers and target gene expression products, because only one target gene amplification amount can be detected at a time, and multiple amplifications are required to detect the amount of different target gene fragments. Multi-channel facilitates multiplex PCR and realizes the function of detecting multiple target genes at one time.
Real-time thermal cycler is mainly used in clinical medical testing, biomedical research and development, food industry, scientific research institutions, etc.