You are viewing this post: ล้างมือ 7 ขั้นตอน | genexpert online
Table of Contents
ล้างมือ 7 ขั้นตอน
นอกจากการดูบทความนี้แล้ว คุณยังสามารถดูข้อมูลที่เป็นประโยชน์อื่นๆ อีกมากมายที่เราให้ไว้ที่นี่: ดูความรู้เพิ่มเติมที่นี่
Cepheid GeneXpert 1, 2, 4, 16
Cepheid is a leading molecular diagnostics company that is dedicated to improving healthcare by developing, manufacturing, and marketing accurate yet easytouse molecular systems and tests. By automating highly complex and timeconsuming manual procedures, the company’s solutions deliver a better way for institutions of any size to perform sophisticated genetic testing for organisms and geneticbased diseases. Through its strong molecular biology capabilities, the company is focusing on those applications where accurate, rapid, and actionable test results are needed most, such as managing infectious diseases and cancer.
ขั้นตอนดูรายงาน GeneXpert online
http://www.tbnfmthailand.org/GFXPert
Preventive Maintenance of GeneXpert Machine
Digital PCR Principle \u0026 Advantages
For more information, please visit our digital PCR learning center : www.genepi.com
One of the greatest challenges in molecular biology is the detection of a rare allele or mutant sequence lost in a dense background of wildtype sequences. This situation is often encountered in oncology for example when trying to detect tumorderived mutant sequences, present in very small amounts in liquid biopsies.
In this animation, the mutant sequence is colored in red and the wildtype is colored in green. Finding the mutant sequence is a typical needle in a haystack problem!
When using standard realtime quantitative PCR, the mixture of DNA molecules is amplified in bulk in a reaction mixture containing PCR reagents, including a Taq polymerase, PCR primers and two types of probes, each specific for the wildtype or the mutant sequence respectively. The wildtype probe is labeled with a green fluorophore, the mutant probe is labeled with a red fluorophore.
During the PCR amplification, the probes specific for the mutant and wildtype sequences anneal to their respective targets and release a fluorescence signal.
However, in a bulk reaction, the signal of the mutant target is in competition with the signal of the wildtype one, and when the mutant sequence is present at a very low fraction, it may not even be detected.
To overcome this problem, Digital PCR relies on a basic principle: partitioning the sample prior to PCR amplification in order to isolate individual DNA molecules in different compartments.
Today, several techniques are employed to achieve the partitioning. This is either done in solid microchambers or done in an emulsion of microdroplets.
When the sample is partitioned, all DNA molecules are randomly distributed into a large number of partitions, such that only one or a limited number of DNA molecules end up in each partition. Even if mutant and wildtype sequences end up in the same droplet, the competition between the two is greatly reduced.
During the PCR amplification, a fluorescence signature is generated within each partition according to its DNA content. One targeted DNA molecule is sufficient to generate a fluorescence signal in a given partition.
Finally, the concentration of wildtype and mutant sequences in the sample is precisely estimated by counting the number of each type of partitions, classified according to the measured fluorescence levels: the nonfluorescent negatives, the greens,… the reds… and the double positives.
Digital PCR also enables the simultaneous detection of multiple targets using a multiplex assay.
Rigorously, a formula based on the Poisson law converts the counted negative and positive partitions into the target concentration of both the wildtype and mutant sequences.
Digital PCR is a powerful tool for the detection of rare events but can also benefit other assays such as copy number variation, by being able to precisely measure less than 2fold differences in copy number, or absolute quantification of nucleic acids, since this technique does not have to rely on comparison with precalibrated standards. Digital PCR is also a great tool for genotyping single cells.
All those assays are currently applied to a wide range of applications such as oncology, infectious diseases, environmental testing, prenatal diagnosis, organ transplant, etc.
How do you want to use digital PCR?
นอกจากการดูหัวข้อนี้แล้ว คุณยังสามารถเข้าถึงบทวิจารณ์ดีๆ อื่นๆ อีกมากมายได้ที่นี่: ดูวิธีอื่นๆGENERAL NEWS
Articles compiled by CASTU. See more articles in category: GENERAL NEWS
does viagra lower your blood pressure viagra over the counter walgreens which presidential candidate was the first spokesman for viagra