Did you stab you in the throat today?
Some time ago, the outbreak of the epidemic in Yangzhou, Nanjing, this sentence is probably the most spoken sentence that everyone has met!
So do you know the principle of nucleic acid testing?
The positive film begins, don't blink, look carefully
Nucleic acid detection mainly refers to polymerase chain reaction, which is commonly referred to as PCR detection, the advantage is that other methods are difficult to achieve the extremely high sensitivity, while the specificity is strong, the degree of automation of the amplification link is high, the window period is short, generally 3-5 days (theoretically, nucleic acids can be detected as long as they infect the mucous membrane), and the relatively closed operating environment can reduce the pollution of the sample to the environment.
01
About PCR
PCR technology is a molecular biology technique that amplifies DNA molecules in vitro by simulating the natural replication process of DNA in vivo, mainly for amplifying segments of DNA located between two known sequences. The DNA amplified by 2ⁿ-fold after several cycles of denaturation, annealing, and extension of the DNA on both sides of the DNA fragment to be amplified and the two oligonucleotide primers complementary to their sides.
Simply put, it is a molecular biology technique for amplifying and amplifying specific DNA fragments, which can be regarded as a special DNA replication in vitro, and the biggest feature of PCR is that it can greatly increase the trace amount of DNA.
In addition, each cycle process of PCR includes three different events of high temperature denaturation, low temperature annealing, and medium temperature extension: ((1) denaturation: heating makes the hydrogen bond between the template DNA at high temperature (about 94 ° C) break and form two single strands; (2) annealing; the solution temperature is reduced to 50 ~ 60 ° C, and the template DNA and primers are complementary and bound according to the principle of base pairing.
forehead......
But the founder of this PCR technology won the Nobel Prize?
02
About Kelly Mullis, the father of PCR
Kelly Mullis, a well-known American chemist, won the 1993 Nobel Prize in Chemistry for inventing the "polymerase chain reaction (PCR)" method for efficiently reproducing DNA fragments.
Born in North Carolina in 1944, Kelly Mullis received his B.S. from the Georgia Institute of Technology in 1966 and his Ph.D. in biochemistry from the University of California, Berkeley in 1973.
On August 7, 2019, Mullis died of pneumonia at the age of 74.
The father of PCR, Kelly Mullis, a controversial legend of "virtue and art"
Curious no, then listen to me slowly!
The controversial legend of "Virtue and Art Double Xin"
1. The university synthesizes psychedelics in its own laboratory
As a child, Mullis did not take the usual path. At the age of 17, he made the first invention in his life, and finally the rocket did not go to heaven, and he almost burned down the house.
Don't look at the skin when you were a child, people graduated from high school and were successfully admitted to Georgia Institute of Technology, one of the three major polytechnics in the United States.
Guess what the buddies are doing?
Because I was interested in chemistry since I was a child, I naturally chose to major in chemistry after entering college. Mullis took advantage of this unique advantage, often synthesizing psychedelics in the laboratory, and only synthetically those that were not classified as contraband.
2. Write a thesis on the drug and be sent to the doctor
After graduating as an undergraduate, Mullis found a position at the University of California, Berkeley, and went on to pursue his graduate and Doctoral degrees. I sniffed drugs in the lab every day, and then went to the next door to pick up nurse MM.
Everyone was tormented by papers when they went to school, and Mullis was no exception.
But the difference is that you scratch your ears and scratch your cheeks and can't write, but people seem to see the flow of time and the explosion of the universe when they are on the drug, and then write out "The Cosmological Significance of Time Reversal" and publish it by Nature Week. Subsequently, Mullis successfully mixed with this paper to get a Doctorate.
3, dislike the boring work, bubble girls, drug discovery PCR technology
After graduation, he went to a private biotechnology company responsible for synthesizing oligonucleotides to provide raw materials. But because the work was too boring, Mullis focused most of his energy on laziness, playing with computers and making gossip.
One day in 1983, Mullis, who had finished his drug and was taking MM home, was on his way to the drug drive, and he saw DNA strands floating in the air, with various colors, red and blue, swirling and entangled in the air...
Mullis immediately stopped the car, took out a pen and paper and wrote.
DNA replication can become two at a time, ten times is 2 to the 10th power, 1024; twenty times there are more than 1 million; 30 times, there are 1 billion, so he discovered the "secret of genes".
After returning to the company, Mullis immediately promoted his ideas, but instead of gaining support, he was also banned from his job because of the hat of messing with the relationship between men and women.
Eventually, Mullis et al. successfully completed the first PCR experiment and published the Science paper.
Mullis was also awarded the Nobel Prize in Chemistry for inventing the polymerase chain reaction (PCR).
Missing out, let's talk about the great significance of PCR
The advent of PCR technology has revolutionized biochemistry, molecular biology, genetics, and modern medicine
In addition to biology and chemistry, he has a grandmaster status in the forensic profession, and without Mullis's invention of PCR, there would be no modern forensic means.