U.S. R & D using LED lights to accelerate the new technology of DNA replication

[LED] Chinese network at the University of California at Berkeley biological engineers developed a new technology, the use of LED light source on / off to improve the heating or cooling the DNA samples of speed, in order to reduce the experimental cost and the speed increase several times.

Luke, a professor of bioengineering, a senior researcher at the study, said: "the PCR Lee system is a rapid, sensitive and inexpensive method of detection. It can be combined with ultra fast genome detection chip, which makes the PCR system in the medical field to develop practical applications. Because this technology can provide real-time blood glucose test results, we can be used in a variety of different environments, whether in rural Africa or hospital emergency room is applicable. "

The photoelectric PCR rapidly heats and cools the electrons on the gold thin layer, and the gene is replicated in a few minutes (source: Luke Lee 's BioPOETS Lab)

According to a study published in July 31 "Light: Science & Application" journal shows that the temperature control technology of ultrafast, greatly expanded polymerase chain reaction (polymerase chain reaction, PCR) clinical research and application of the test, the original more than one hour of detection time, greatly reduced to just a few minutes.

Polymerase chain reaction (PCR) test by single copy DNA sequences, making copies of thousands to millions, from the study of forensic analysis and copy to a paternity test, this technology has become an important part of the application of genetics. The PCR test was used in the initial diagnosis of genetic and infectious diseases, and was used to analyze the DNA samples of ancient mummies and mammoths.

In 1993, Kelly (Kary Mullis) and (Michael Smith) made the PCR test has a major breakthrough in the contribution of modern science, and thus was awarded the Nobel prize.

The use of LED, California University of Berkeley researchers in thin gold interface electron heating and DNA solution. They calculate the rate of heating the solution, about 12.7 degrees Celsius per second. The temperature can reach 6.6 degrees Celsius per second amazing speed.

Professor Lee, a senior researcher at the Institute of bioengineering, Luke, said: "PCR is a very useful and widely used test in the medical community, but the existing PCR testing system is relatively time-consuming. In view of the fact that the traditional heater has large power consumption and high cost, it is usually tested in the laboratory. Because the whole process takes about an hour, it is not suitable for real-time blood glucose detection. Our system is able to test results in a few minutes. "

Ultrafast optoelectronic PCR test using LED light on the surface of the thin gold copy of gene samples (Photography: Jun Ho Son)

The time consuming of traditional PCR test is that the process of heating and cooling DNA solution is too long. PCR detection requires repeated temperature changes to be performed at an average of 30 cycles between the three temperature points to replicate the sequence of genes. This process involves the disassembly of the DNA sequence, and the combination of single chain and its chain. With each cycle of heating and cooling, the number of DNA samples will double.

In order to improve the speed of the temperature cycle, Professor Lee and his team used the principle of plasma optics (plasmonics), or the so-called interaction of light and electrons on the metal surface. When the light is received, the free electrons become active and begin to vibrate. Once the light is cut off, the vibration and heat disappear.

Because of its easy to absorb light, gold has become a popular metal interface for the electro optical heat energy. In addition, its added value is able to be implanted in biological systems, so it can be used in biomedical engineering applications. In the study, the researchers used a 120 nm thick gold layer, about the width of a rabies virus. Gold is placed on a microfluidic chip for loading PCR mixture and DNA samples.

The light source is a ready-made LED lamp placed below the PCR chip. The LED lamp is adjusted to the maximum 450 nm wavelength for maximum efficiency of light heating. The researchers were able to repeat the whole cycle 30 times in a matter of minutes from 55 degrees Celsius to a temperature of around 95 degrees Celsius, the researchers said. They tested the efficiency of the copy DNA of the optoelectronic PCR system and found that the results were better than the traditional PCR test.

The study's lead researcher Jun Ho Son is a postdoctoral fellow at professor Berkeley's laboratory in Lee. Bill and Melinda Gates Foundation and the South Korean National Research Foundation sponsored the study.

This study can be foreseen, LED and biotechnology combined with the example, the future is expected to be more and more, not just plant lighting, medical beauty light source. (Chinese LED net Emmachang)

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