American research and development use LED lamp to speed up the new technology of DNA replication

Bioengineers at the University of California, Berkeley, have developed a new technology that uses the opening / closing of LED light sources to increase the speed of heating or cooling genetic samples to reduce the cost of the experiment and increase the speed of the experiment several times.

Professor Luke Lee, a professor of bioengineering, said: "the optoelectronic PCR system is a fast, sensitive and low price detection method. It can be combined with the ultra fast genome detection chip, which can make the PCR system develop practical use in the medical field. Because this technology can provide real-time blood glucose test results, we can use it in a variety of environments, both in rural and hospital emergency rooms in Africa.

The photoelectric PCR quickly heated and cooled the electrons on the thin layer of gold and made a gene copy in a few minutes (Luke Lee 's BioPOETS Lab).

According to the study in the 31 Journal of July in the Journal Light: Science & Application, this super fast temperature control technique has greatly expanded the clinical and research applications of the polymerase chain reaction (PCR) test, and reduced the detection time of the original more than one hour to a few minutes.

The polymerase chain reaction (PCR) test creates thousands to millions of copies by replicating a single DNA sequence, from replicatomics to forensic analysis and parent-child identification, which has become an important link in genetic applications. The PCR test is used for the preliminary diagnosis of hereditary and infectious diseases, and is used to analyze the DNA samples of ancient mummies and long hair images.

In 1993, the discoverer, Kary Mullis and Michael Smith, made a major breakthrough in the PCR test and made a Nobel prize for the contribution to modern science.

Using LED, researchers at the University of Berkeley, California, can heat electrons and DNA solutions on a thin layer of gold interface. They calculate the speed of the heating solution, about 12.7 degrees centigrade per second. The cooling rate can reach an amazing speed of 6.6 degrees centigrade per second.

Bioengineering professor Luke Lee, a senior researcher at the research, said: "PCR is a very beneficial and widely used test in the medical community, but the existing PCR testing system is relatively time-consuming. Considering that the traditional heating apparatus is expensive and expensive, it is usually carried out in the laboratory. As the whole process takes about an hour, it is not suitable for real time blood glucose testing. Our system can get the test results in a few minutes.

Ultra fast photoelectric PCR test uses a LED lamp to copy a gene sample on a thin layer of gold surface (Photography: Jun Ho Son)

The time time of the traditional PCR test is that the process of heating and cooling the DNA solution is too long. PCR detection requires repeated temperature changes to perform - an average of 30 cycles between three temperature points - replicating the sequence of the gene. This process involves the DNA sequence of dismantling double smelting and combining the single smelting with its corresponding chain. With each heating cycle, the number of DNA samples will grow twice as much.

To improve the speed of the temperature cycle, Professor Lee and his team used the principle of plasmonics, or the so-called interaction between light and electrons on the metal surface. When the light is received, the free electrons become active and begin to vibrate and produce heat. Once the light is cut, the vibration and the heat will disappear.

Gold has become a hot metal interface for this kind of electro thermal energy heating because of its easy absorption efficiency. In addition, its added value is able to be implanted in a biological system, so it can be used for biomedical engineering applications. In the study, the researchers used 120 nanometers of gold thin layer, probably the width of a rabies virus. Gold is placed on a microfluidic chip to load the PCR mixture and DNA samples.

The light source is a ready-made LED lamp under the PCR chip. The LED lamp is adjusted to the maximum radiation efficiency of the maximum radiation of 450 nanometers. The researchers can reheat the whole cycle 30 times from 55 degrees Celsius to 95 degrees Celsius in 5 minutes. They tested the efficiency of the optoelectronic PCR system replicating sample DNA, and found that the results were better than the traditional PCR test.

Jun Ho Son, the leading researcher in the study, is a Berkeley postdoctoral researcher in Professor Lee's research room. Bill and the Melinda Gates Foundation and the South Korean National Research Foundation supported the research.

It is foreseeable that the combination of LED and biotechnology is expected to be more and more in the future, not only the light of plant lighting and medical beauty. (translation / China LED network Emmachang)

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