MTL - The Science Fiction World of Xueba-Chapter 397 laboratory

Although it is much smaller than the hive laboratory, compared to the real-world life science laboratories, the Kempten base underground laboratory is still a behemoth.

In the laboratory, there are spectrometers, chromatographs, gene introduction instruments, protein purification systems, cell fusion instruments, electrophoresis instruments, atomic absorption spectrometers, virus immunofluorescence analyzers, chromatographs, biochemical analyzers, and freezers commonly used in life science research. Electron microscopy, etc. There are also many instruments and equipments that Pang Xuelin has never seen.

For example, an artificial uterus used for somatic cell cloning. The surface of this artificial uterus looks like a huge glass jar, connected through various pipes, and can provide a series of nutrients and growth hormone to the cloned person inside.

According to Spruce, this artificial uterus can allow a clone to grow from a fertilized egg state to a Chéng Rén state within six months.

Pang Xuelin was so surprised. The glass jars filled with Alice clones he had previously seen at the underground base in Irvine were probably the so-called artificial uterus.

In addition, there are some instruments that are also very interesting.

For example, a 4D-EM high-resolution cryo-electron microscope for analyzing the three-dimensional structure of proteins.

This frozen electron microscope was also the first time Pang Xuelin had seen.

In the real world, cryo-electron microscopy can be divided into three major categories, namely cryo-transmission electron microscopes, cryo-scanning electron microscopes, and cryo-etched electron microscopes.

Frozen transmission electron microscopes are the most common. Usually, a sample freezing table is installed on the ordinary transmission electron microscope to cool the sample to the liquid nitrogen temperature (77K). Used to observe temperature-sensitive samples such as proteins and biological sections. By freezing the sample, the damage of the sample by the electron beam can be reduced, and the deformation of the sample can be reduced, thereby obtaining the true sample morphology.

Cryo-SEM is a fast, reliable and effective method to overcome the problem of sample moisture. This technique is also widely used to observe some "difficult" samples, such as those with unstable electron beam sensitive samples.

The third type of freeze-etching electron microscope allows the sample to be frozen to make its fine structure close to the state. After the sample is freeze-etched to freeze, it can observe the fine structure of different splitting surfaces, so that the membrane structure and internal structure of the cell can be studied. Containing structure, freeze-etched samples, and replica films prepared by platinum and carbon spray coating, have a strong three-dimensional sense and can withstand electron beam bombardment and long-term storage.

In the real world, cryo-electron microscopy is a high-end equipment in the field of biology. The price is about 6 million US dollars, and there are not many units in China. The largest cryo-electron microscopy center is located in Southern University of Science and Technology in Shencheng.

But in the Kempten underground laboratory, these three cryo-EMs have disappeared, but replaced by 4D-EM cryo-EMs.

This cryo-electron microscope does not exist in the real world. It uses a femtosecond laser instead of ordinary electrons to present an ultra-fast image, which greatly improves the resolution of the sample.

And after the introduction of Spruce, Pang Xuelin discovered that the emergence of this electron microscopy technology allowed scientists to analyze the evolutionary path of the three-dimensional structure and function of certain protein molecules.

This is a very important academic achievement.

According to the theory of evolution, a large number of structurally and functionally diverse protein collections in nature have evolved from a limited number of protein ancestral molecules.

But scientists have found in research that protein molecules with new functions can be evolved in a short time in nature.

For example, shortly after the appearance of some man-made chemicals, enzymes specifically decomposing them appeared in nature.

After several new antibiotics were put into use for several decades, new proteins with drug-resistant functions appeared in some microorganisms.

The basis of protein structure and function evolution is the change of amino acid sequence.

Sequence changes are most likely to occur in evolution. These are typical mutations in which a single amino acid residue type is changed at a particular position, a new sequence fragment is inserted or a sequence fragment is lost, and so on.

In the real world, due to the relatively limited means for studying and evolving the structure of proteins, it is difficult for scientists to clarify the physical and chemical mechanisms behind changes in protein structure and function.

In the world of biochemical crisis, with the help of 4D-EM cryo-electron microscopy and atomic probe chromatography, scientists have been able to clearly understand the evolution of certain protein molecules.

In addition, Pang Xuelin saw a new gene editing technology in the laboratory.

In the real world, there are two main types of gene editing technology, one is CRISPR / Cas9 technology and the other is single base editing technology.

The so-called CRISPR is actually a repeated sequence in the genome of prokaryotes. It is an immune weapon generated by the fight between bacteria and viruses in the history of life evolution. In short, the virus can integrate its own genes into bacteria. Your own gene replication service.

Bacteria have evolved the CRISPR / Cas9 system in order to eliminate the virus's invading genes. With this system, bacteria can silently cut off the virus genes from their own genome, which is a bacteria-specific immune system.

Microbiologists have learned that bacteria have multiple immune functions to remove foreign virus genes. The typical model is to rely on a complex that can be directed to find the target DNA sequence under the guidance of a piece of RNA and then excise the sequence. .

Many bacterial immune complexes are relatively complicated. Among them, scientists have mastered the manipulation of one protein Cas9, and have removed the DNA of various target cells.

This technology is called the CRISPR / Cas9 gene editing system and has become the hottest technology in the life sciences in the real world.

However, in practical applications, CRISPR / Cas9 technology has off-target effects, and there are serious side effects in applications such as gene therapy.

The BE3 single-base gene editing technology also has the problem of off-target. It can even cause a large number of oncogenes and tumor suppressor gene mutations, which also has great safety risks in practical applications.

This is also an important reason why He Jiankui, an associate professor of the University of Science and Technology of China, two years ago, was severely condemned for his "gene editing baby" experiment, and it was also a starting point for prohibiting genetic manipulation of human embryos for reproduction purposes.

Because of this, in the real world, human gene editing technology is still in its infancy.

Humans have also been searching for a new generation of better gene editing tools than CRISPR / Cas9.

In 2016, China had a sensational Han Chunyu.

Associate Professor Han Chunyu from HB University of Science and Technology claims to find a new gene editing tool, the NgAgo / gDNA system, which is much more accurate and efficient than the CRISPR / Cas9 system.

This paper was published in the top international journal "Nature · Biotechnology", and aroused strong attention at home and abroad, and was even hailed as a "Nobel Prize" experimental result by some media.

But shortly thereafter, the content of the paper fell into an irrepeatable controversy.

Because biological experiments are not as repeatable as physical or chemical experiments due to operational, environmental, and experimental subject complexity. For example, PCR on complex templates is difficult to guarantee every time, and experiments on some cells are greatly affected by cell status and cell source.

Even for many S-level articles, there will be many experimental results that cannot be repeated.

In the end, Han Chunyu's leave nothing to be desired.

Now, Pang Xuelin has seen a new gene editing technology with his own eyes in the underground laboratory in Kempten Town.

This technique is called heDNA editing tool.

The accuracy of this tool for gene splicing, gene knock-in and knock-out is above 99.99999%, and there is almost no problem of off-target or mutation.

It is because of this editing technology that life science technology in the biochemical crisis world can be so amazing.

This is also an important reason why umbrella companies can develop T virus.

"Professor Berkeley, where has the laboratory's T virus research progressed?"

Pang Xuelin is interested in the principle of the T virus.

Berkeley groaned for a moment and said, "Mr. Pang, we can basically be sure now that the principle of the T virus is to change the regenerative properties of the cells and speed up the metabolism and repair capacity of the cells. This also makes many zombies difficult to be killed by physical attacks. When humans are infected with T virus, they are obstructed by the human immune system. Leukocytes will try to kill the infected cells, which will cause a large amount of necrotic tissue in the human body. In order to repair the loss of tissue and restore the function of the immune system, a large amount of Food provides a source of material and energy, and the infected person develops a strong appetite.

The appetite of these creatures is greatly increased. As long as they see, hear, and smell the existence of the creature, they will immediately rush to hunt down the prey he is staring at. Because of this, the zombies will become infected with the T virus. So violent.

It should be noted that under normal circumstances, the brain is protected by a tissue isolation called the blood-brain barrier, and does not contact immune cells, so if the barrier is not damaged, the brain is very likely to complete the mutation relatively well. As a result, zombies are still able to walk upright and foraging. That's why the zombies die completely after we hit them with a gun ... "

Pang Xuelin said: "How long do you think this crisis will continue to end? Will those zombies die in the future?"

Berkeley said: "Zombie activities also require energy supplements. At present, more than 99% of the world's people have been infected with zombies, which has led to increasing food shortages in cities. When food is added, zombies can only maintain basic vitality by corroding their bodies. According to our estimates, zombies will die on a large scale in five years and ten years slowly, but only then will there be left on the planet. The number of people will be unknown. "

Pang Xuelin nodded and didn't ask any more.

It's almost as he guessed.

For those infected zombies, the best way is to wait for his death.

What really made Pang Xuelin feel tricky was the ambitions of Spencer, Muskow, and William Birkin from the umbrella company.

Pang Xuelin could faintly guess Spencer's thoughts.

For Spencer, after being infected with T virus or G virus, they have become monsters in the eyes of ordinary humans.

In a sense, they have become other species.

This is why Spencer was able to launch a biochemical crisis on earth without any fear.

In the eyes of these people, the destruction of humankind is just the extinction of aliens.

What they really want to do is lead the umbrella company to find a new, flawless evolutionary path.

Once they succeed, another human-like species will be born on Earth in the future.

They will also become the ancestors of this species and become true gods.

And Pang Xuelin wants to preserve humanity, and sooner or later he and Spencer will go to the opposite side.

Fortunately, Pang Xuelin still has time to buffer, and the body transformed by the genetic optimizer has made Spencer recognize the existence of Pang Xuelin.

Therefore, as long as they do not make progress on the T / G virus research one day, they will not easily start with Pang Xuelin.

"We must find a way to develop an antidote against the T virus. Only Spencer and his men without the blessing of the T virus are the best time to counterattack."

After visiting the underground laboratory.

Pang Xuelin was about to say something to Spruth who was next to him, and he saw Jill hurried over and said loudly, "Professor Pang, it's not good, the umbrella company sent Dr. Ashford. Here, Alice is going to kill him. Claire is now trying to stop Alice. "

Pang Xuelin paused for a moment and said, "Let's go and see."

Back on the ground ~ www.novelbuddy.com ~ Pang Xuelin saw the gate of the manor. Alexander Ashford was sitting in a wheelchair. Alice held a knife against Dr. Ashford's neck. The umbrella company sent him to protect Ash Ford's soldier pointed Alice at the gun, and Claire was trying to persuade both. "

"What are you doing?"

Pang Xuelin stepped forward and caught Alice's long knife directly.

Alice struggled slightly, and seemed worried that she would hurt Pang Xuelin and didn't exert much force.

She stared at Pang Xuelin. "This guy is not a good guy. Why are you protecting him?"

Pang Xuelin pulled the knife out of Alice's hand with a little force, and laughed, "Dr. Ashford is his own."

Speaking, Pang Xuelin blinked at Alice.

Alice frowned, looking at Pang Xuelin, and said after a while: "Remember what you said to me some time ago."

After all, she turned and left.

Pang Xuelin turned his head and looked at Ashford. "Dr. Ashford, sorry, my companion has a hot temper."

Ashford waved his hand and motioned his gun to be lowered, saying, "It's all right, Professor Pang, I'm glad to see you again."

Pang Xuelin smiled: "I'm also glad to see you again, by the way, Doctor, Angela? Why didn't she come?"

Pang Xuelin is very fond of the bright little girl.

A bitter smile on Ashford's face said, "Mr. Spencer was worried that Angela would not adapt to life here, so she didn't let her come over."

Pang Xuelin nodded for a moment and nodded: "So it is."