echemi logo
Product
  • Product
  • Supplier
  • Inquiry
    Home > Biochemistry News > Biotechnology News > The principle, application and research progress of molecular beacons.

    The principle, application and research progress of molecular beacons.

    • Last Update: 2020-10-21
    • Source: Internet
    • Author: User
    Search more information of high quality chemicals, good prices and reliable suppliers, visit www.echemi.com

    abstract
    molecular beacon technology is an analytical technique based on the principle of fluorescent resonance energy transfer phenomenon (FRET) and base complementary pairing. Molecular beacon, as a fluorescently labeled molecular probe with strong specificity and high sensitivity, has become an important research tool for
    basic medicine
    and biology. This paper focuses on the basic principles and applications of molecular beacons, and gives a brief introduction to their research progress in recent years.
    1 Introduction
    In the
    gene
    era and the
    protein
    era, there is an urgent need for a biometric probe with high sensitivity and affinity for qualitative and quantitative testing. Tyagi and Kramer first established molecular beacon technology in 1996, which was soon widely used in medicine, biology,
    molecular biology
    ,
    clinical medicine
    and chemistry.
    molecular beacon technology is highly specific and easy to operate and sensitive, especially for real-time quantitative detection and even for live analysis. Molecular beacons are also
    in areas
    clinical diagnosis, genetic testing, and other fields. In recent years, many improvements have been made to the structure of molecular beacons, and many new molecular beacons with more characteristics have been developed. With the development of molecular beacons, the technology will certainly play its advantages in more fields.
    principle of 2 molecular beacons
    Molecular beacons are fluorescently labeled oligopolytic
    nucleotides
    chains, generally containing 25 to 35 nucleotides. In structure, molecular beacons can be broadly divided into three parts:
    (1), ring region: generally composed of 15 to 30 nucleotides, can be specifically combined with the target molecule
    ;
    (3), fluophores and quenching groups: fluorophores are generally connected at the 5th end, quenching groups are generally connected at the 3x, commonly used 4-(4-medoxymethyl anitrobenzene) benzoic acid (DABCYL) as quenching groups. According to Foerster's theory, the central fluorescent energy transfer efficiency is inversely inversely related to the six times the distance between the two. Therefore, fluorescence is produced only when a certain distance is reached between the fluorescent and quenching groups.
    free state, the molecular beacon is card-type structure, so that the fluorescent and quenched base groups are closer (about 7 to 10 nm). At this time, the fluorescence resonance energy transfer occurs, so that the fluorescence emitted by the fluorescent group is absorbed by the quenched substrate and emitted in the form of heat, the fluorescence is almost completely quenched, the fluorescent background is very low. When the molecular beacon binds to the target molecule, the distance between the fluorescent and quenching group increases, thus restoring almost 100% of the fluorescence of the molecular beacon. Moreover, the detected fluorescence intensity is directly related to the target marker in the solution.
    3 the main factors affecting molecular beacons
    the distance between fluorescent and quenching groups is the most important factor affecting molecular beacons. According to Foerster theory, the distance between fluorescent and quenched groups directly affects the intensity of fluorescence.
    , temperature is also an important factor affecting molecular beacons. At lower temperatures, molecular beacons can maintain the card-issue structure. At higher temperatures, molecular beacons will not be able to maintain their card-issuing structure or even stretch it to random lines, causing fluorescent and quenched groups to separate, resulting in fluorescence and false positive results. It has been shown in literature that the melting chain temperature depends on the length of the stem area, the G-C content and the ion strength of the buffer.
    study of the effect of temperature on molecular beacons, such as Bonnet, found that the fluorescence intensity of the system appeared as a process of first weakening and then strengthening. In this regard, Bonnet et al. explained as follows:
    at lower temperatures, molecular beacons and targets combine in an S1 state, fluorescence. As the temperature increases, the molecular beacon separates from the target and the molecular beacon reverts to the card-issued structure, known as S2, thus reducing the fluorescence intensity. The temperature continues to increase, which will lead to the molecular beacon melting chain, S3 state, fluorescent group and quenching group separation, resulting in fluorescence recovery.
    environmental pH is also a factor affecting molecular beacons. The pH is too high, and the carding structure of the molecular beacon may be damaged, resulting in false positive results. In addition, the purity of molecular beacons will also have an impact on molecular beacons.
    .
    This article is an English version of an article which is originally in the Chinese language on echemi.com and is provided for information purposes only. This website makes no representation or warranty of any kind, either expressed or implied, as to the accuracy, completeness ownership or reliability of the article or any translations thereof. If you have any concerns or complaints relating to the article, please send an email, providing a detailed description of the concern or complaint, to service@echemi.com. A staff member will contact you within 5 working days. Once verified, infringing content will be removed immediately.

    Contact Us

    The source of this page with content of products and services is from Internet, which doesn't represent ECHEMI's opinion. If you have any queries, please write to service@echemi.com. It will be replied within 5 days.

    Moreover, if you find any instances of plagiarism from the page, please send email to service@echemi.com with relevant evidence.