日韩国产亚洲欧美成人图片

  • <center id="2imgo"><menu id="2imgo"></menu></center>
  • <u id="2imgo"></u>
  • Science: Sequencing mutations in the database are caused by experimental processing

    One study pointed out that some of the sequence variations found in DNA samples may actually be caused by damage during sample processing. Researchers from NEB (New England Biolabs) developed a new algorithm to evaluate these lesions and recommend DNA repair enzymes are used during sample preparation to correct this problem.

    The study, published in the February 16 issue of Nature, said Thomas Evans, one of the authors of the article, "this damage is more common than we expected," and such an error is likely to confuse real low-frequency somatic cells. mutation.

    As we all know, DNA samples extracted from old samples with long-term preservation, or formalin-fixed, paraffin-embedded tissues are prone to cleavage and chemical modification, resulting in mutations that are not present in living organisms. But the latest research shows that, in fact, any DNA sample may have such artificial mutagenic damage, such as DNA sonication, that is, using sonic energy to agitate DNA fragments for amplification and sequencing, it is possible to induce mutations. Oxidative damage.

    Such mutations sometimes occur only in a small number of samples and therefore do not cause much trouble. However, in cancer biology, subcloning recognition is increasingly emphasized, as well as mutations in free plasma DNA detected in plasma, both of which are small in the sample. "This article is a good warning article," said Marc Ladanyi, a molecular oncologist at the Sloan/Cadelin Cancer Memorial Research Center in New York, who was not involved in the study.

    Science?????°????o“??-????μ??o??a??????ˉ???éa??¤????é€???????

    NEB researcher Laurence Ettwiller et al. designed a new algorithm to calculate the extent of this damage in DNA sequencing samples. The basis of this algorithm is that oxidative damage to DNA during sonication converts guanine into 8-oxoguanine, which is used as thymine during sequencing.

    Comparing the sequences of the two complementary strands, these altered guanines are considered to be mismatch sites, one strand reads thymine, but the complementary strand shows cytosine (which can be paired with guanine). On the other hand, naturally occurring guanine-thymidine mutations will appear in their own paired adenine. Therefore, this method determines the degree of damage by evaluating the degree of mismatch of thymine by comparing the first and second sequencing results.

    Using this algorithm, named Global Imbalance Value (GIV), the researchers examined data from the Thousand Human Genome and Cancer Genome Atlas project and found that in the thousands of genome data. % showed an imbalance score indicating the damage, and the Cancer Genome Atlas project was as high as 73%.

    The researchers suggested adding a DNA repair enzyme mixture to the DNA sample during the preparation process, which resulted in a stable oxidative damage rate.

    "(This article) proposes a solution to repair DNA using a cocktail cocktail of enzymes," Ladanyi said. But he also pointed out that "the author of the article is from NEB, and the solution to the problem is to use the NEB repair system, so there is a conflict of interest."

    In this regard, Ettwiller said that although the research team used NEB enzyme to repair damaged DNA samples, they did not say that this would apply to all DNA preparation processes.

    "We are indeed selling this enzyme mixture for repairing the upstream DNA, but we are not packing it, we will continue to evaluate it," Evans said.

    P6 Rental Indoor

    Indoor Full Color LED Display P6 Rental, which made from die cast cabinet, it is easy maintenance. Indoor Rental LED Display using the distribution and modular design to improve the stability of the LED Screen control system. P6 LED Display widely used in Indoor Rental Projects, like Party, Conference, Concert, Stage Play etc.

    P6 the tried and tested 3535 packageing technogoloy, pixel 27777 per square meter, large lighting angle, uniform heat dissipation, large angle, colorful and vivid. Using the distribution and modular design to improve the stablility of the system. Each of the light-emitting points are red, green, blue, which display body with computer as control center, with perfect program production software and playing software, electronic display screen and display window to form one.

    1)Salty spray test, high voltage test, varying temperature test, waterproof test, vibration test.
    2)Long service time and low attenuation by applying dual channels for heat dissipation.
    3)High protection grade of IP65 achieved by patented mask design with waterproof and dustproof fuction.

    Looking forward your long term cooperation!

    P6 Rental Indoor,Indoor Led Screen,Led Screen Price,P6 Indoor Rental Led Screen

    Shenzhen Jongsun Electronic Technology Co., Ltd. , https://www.jongsunled.com

    日韩国产亚洲欧美成人图片
  • <center id="2imgo"><menu id="2imgo"></menu></center>
  • <u id="2imgo"></u>