Chen Gong took less than 30 minutes to complete all the test papers.

The rest of the time, he was thinking about something......

It's a loss!

This time, I spent money on the exam.

What I originally hoped to see was a wonderful topic designed by a group of top biochemical experts, who couldn't sleep all night, spent a lot of energy, and racked their brains.

Then there is a cultural game at the level of thinking.

Finally, in this game, discover your true self, check and fill in the gaps, and improve yourself.

That's what an exam should really do!

It is also the most romantic story in Chen Gong's mind.

But...... I never thought that after I came, I would do the type of question I designed?!

I had a left-right fight with myself.

Of course, in fact, there is no duplication of the question and Chen Gong's mock questions.

But at the level of Chen Gong, can't you see that this is a kind of thinking angle?

In this set of questions, most of the questions are combined with their own ideas and angles, especially in the perspective of inducing the development of biochemical research, which is incisive.

Although it is undeniable......

This questioner is really a bit level, but ...... No matter how level you have, you can't escape Chen Gong's thinking mode when he came up with the question.

So, this time the written test ...... For Chen Gong, there is really nothing to gain.

He didn't feel the joy of playing with the masters!

That......

What good can it be other than to get a useless high score?

Hello life!

Studying, in particular, is never for an ethereal 100-point score.

This kind of low-level fun, Chen Gong was tired of the happiness of 100 points when he was in the fourth grade of primary school.

What he wants is that kind of hearty thinking level games and disputes!

Can ...... now

What I saw was still a ...... full of boring, boring, and boring 100 marks for the paper.

It's really a big loss!

How does Chen Gong think and how to lose......

"Hello, I'll hand in the papers!"

"Sorry, you can't submit your papers before the end of the exam."

The invigilator interrupted Chen Gong's unrealistic fantasies and destroyed the child's last bit of escape.

Chen Gong took a deep breath and glanced around.

Looking at everyone's sad faces, watching everyone calculate every question with a rigorous face and think about every detail.

Chen Gong is really envious!

Maybe......

They are much happier than themselves, and at least they can see a wonderful test paper.

Ay......

Chen Gong sighed and looked out the window, maybe only Bai Yun could understand what he meant at this time, right?

Chen Gong, who was bored and boring, could only close his eyes and began to simulate the skill assessment in the afternoon.

After all, such a question made him not interested in checking.

Taking a second look is disrespectful to one's own expertise.

However, Chen Gong thinks that is because this assessment is too low-level?

Those high-level assessments, will they be better?

Thinking of this, Chen Gong was a little moved.

……

I finally made it to the end of the exam.

Chen Gong got up anxiously, left the examination room, and was about to drive to the anatomy test center.

And when I went out, I happened to meet Yang Li.

It's just that...... The other party's eyebrows were tight, and he looked a little sad.

Seeing this scene, Chen Gong couldn't help but feel envious.

Yang Li saw Chen Gong and said hello: "Chen Gong, how did you do in the exam?" ”

Chen Gong sighed and shook his head, how is it? Extremely lost!

Yang Li was helpless: "I also heard that this assessment is a new model of examination questions conducted by our domestic experts in the field of biochemistry." ”

"I started ...... Didn't care! ”

"However, I didn't expect the difficulty to increase so much."

"It's not just you and me, it's a lot of people, look at it...... Most people don't quite fit in. ”

"It's definitely going to be difficult!"

"However, these questions are really interesting, I am very happy to do them, and I even feel that I can improve by doing them."

Chen Gong looked at Yang Li and said seriously: "Instructor, I really envy you!" ”

Yang Li was stunned for a moment, and then smiled: "What do you envy me?" Oh...... Actually, I've always been in a good state of mind. ”

"Besides, the difficulty of the question is difficult for everyone, and it is not for one person."

"I can only say that I am not so sure in my heart, so I will be worried."

"Actually, don't worry, you're still young, you're only a sophomore, how many of them are better than you?"

Yang Li thought that Chen Gong was uncomfortable because he didn't do well in the exam, so she opened her mouth to comfort Chen Gong.

And then, Chen Gong suddenly said: "I really envy you, you can encounter difficulties in the exam, find your own shortcomings, and compare them with the questions." ”

"Hey......"

"I can't!"

"For me, in addition to giving me a boring and useless 100 points, this test question is not very useful for judging my personal ability, testing my shortcomings, and even improving my overall strength."

"Hey, I really envy you, if I were like you, I would be very happy if I scored so much."

After speaking, Chen Gong shook his head and fiddled with the car key in his hand: "I have to go to the next exam room." ”

"Goodbye, instructor!"

"Bless me in the next exam room, I can encounter some questions that I don't know!"

After speaking, Chen Gong kicked the accelerator, the tram started, and he walked away in an instant.

Leaving Yang Li standing in the wind, messy for a long time, she didn't come back to her senses for a long time......

What do you mean by ...... "Hey, I really envy you, if I were like you, I would be very happy if I scored so much in the test." ”

Listen to this is human words?

And this......

"Aside from the boring 100 points, ...... for my abilities"

"I really envy you for being able to score so much......

Gradually, Yang Li completely understood what was going on.

She stood there like a repeater, recalling Chen Gong's words several times.

But I still didn't understand what it meant.

Is 100 bad?

This......

It's the first time Yang Li has seen such a person, masochist!

Still not happy about getting a high score?

Also, envy their own dishes?

Is there such a boast!

After a long time, Yang Li came back to her senses, and the corners of her mouth twitched.

Boy!

You bastard!

Are you here to take the exam?

Aren't you here to smash the field?

Yang Liqi's teeth itched.

……

Obviously, Chen Gong couldn't hear it.

After he arrived at the anatomy examination room, he carefully read the paper twice, only to realize that fortunately he had not done it......

Otherwise, it will be a loss again!

The morning exam questions ended successfully after Chen Gong successfully answered each question.

At noon, I drove the car and had a brief lunch near the biochemical experiment skills test center.

Then it's a matter of being patient.

There are obviously a lot of people around who come to participate in the assessment.

Everyone was talking about the morning exams.

"This year's biochemistry is too difficult!"

"Who's to say it isn't? I've never seen this type of question, it seems simple, but it's actually full of traps! ”

"Hey...... It's so difficult, I feel like I may not be able to pass the written exam this year! ”

"Before the results come out, don't talk about yourself, you have to think like this, what can you do if you pass the written test? It's about the same as the skills......"

“…… You know how to comfort people! ”

……

Listening to everyone's words, Chen Gong was really envious.

Although Chen Gong didn't know why the type of test questions was so similar to the type of questions he designed for the biochemical secret paper mock questions.

But...... That's not a bad thing after all.

Because he knows very well that this type of question can improve people's biochemical thinking and improve biochemical association ability.

If you really use this set of questions to assess, you can indeed screen out a lot of good talents.

Afternoon!

At two o'clock, everyone began to enter the examination room, seeking the beginning of the exam.

First of all, before starting, it is a lottery to receive your own skill assessment items.

This level is a random selection of skills for assessment.

Each person has a limited amount of time, and within 30 minutes, they are required to complete the experimental project. 、

Chen Gong quickly got his envelope, but he couldn't open it.

Once you need to enter the exam room, hand the envelope directly to the examiner, and then start the process after the examiner informs you of the requirements of the project.

At this time, Chen Gong also found that most of the people who came to participate in the experimenter assessment were relatively young.

Because there is an age limit for the junior experimenter qualification certificate, you must be under 35 years old to participate.

The so-called primary experimenters actually include first-level and second-level experimenters.

When it reaches the third level, it belongs to the intermediate experimenter.

And the fourth, fifth and sixth grades, which belong to the experimental specialists, are rare.

In this way, Chen Gong's age does not seem to be abrupt.

Soon!

With the ringing of the bell, the first batch of candidates began to enter the examination room.

Chen Gong stood up and walked towards his room.

After entering, the two examiners sat on chairs in the laboratory, and Chen respectfully submitted the envelope.

Liu Rong is a member of the Laboratory Department of the First Affiliated Hospital of Shanhe Medical University, and is also a staff member of the Biochemistry Research Institute of Dongshan Experimental Base.

Today's partner with her is Zhuang Baoshan, director of the Biochemistry Laboratory of Shanhe University of Traditional Chinese Medicine.

The two of them each had a form in their hands at this time.

The dense blank space above is the scoring area.

The test skills assessment is actually the details.

There are hidden pluses and minuses in many places.

In addition, there is a certain proportion of the candidate's ability to adapt to the situation, and the experimental accident is evaluated...... and other comprehensive judgments.

Because it is impossible to succeed in every experiment.

Accidents happen from time to time, and at this time, mentality and strain will be very important.

Liu Rong couldn't see the candidate's situation, and after seeing Chen Gong, she nodded.

"Your assessment item today is: the isolation of subcellular structures."

"Candidates, please be prepared."

"In five minutes, start your operation."

"The relevant utensils and test materials are already next to our separator."

After Chen Gong listened, there was no surprise.

The isolation of subcellular structures can only be said to be not difficult, nor is it easy.

After all......

This assay involves isolating nuclei, mitochondria, microsomes, and cytoplasm.

And this test, what needs to be mastered is ultracentrifugation technology.

The so-called ultracentrifugal technology is more difficult than ordinary centrifugal techniques, and it is necessary to apply strong centrifugal force to separate, concentrate and purify the substance according to the sedimentation coefficient, mass, buoyancy factor and other different methods of the substance.

In recent years, ultracentrifugation technology has become more and more mature and has become an important technical method for isolating, purifying and identifying biological polymers.

Therefore, ultracentrifugation technology is not only an introductory technology for biochemistry, but has even become one of the main technologies of bioengineering.

That's the fun!

Chen Gong took a deep breath and walked to the side of the centrifuge.

After seeing the instrument, Chen Gong's eyes suddenly widened and he was a little happy.

Boy!

Swiss centrikon T-1055!

That's a good thing.

Chen Gong had only dismantled this thing two or three times.

Although there are a lot of these instruments in their school laboratory, they are all very expensive, and they are closely watched by those experimenters on weekdays.

The laboratory that Yang Li often goes to is the German K-355 model, which is an old-fashioned model.

All indicators of ultra-high speed are not as accurate as this!

In this regard, the T-1055 is very strong.

Chen Gong has used it several times, but it is just ...... I had only dismantled it two or three times, so when I saw him, my hands were instinctively itchy.

However, today is the assessment site, and Chen Gong knows that he can't mess around......

So, after some adjustments, he decided to start his own operation.

According to conventional experimental methods, Chen Gong needs to calculate the centrifugal force according to Newton's second law.

The centrifugal force (Fc) depends on the mass of the particle (m) and the centrifugal acceleration (a), i.e., Fc = m a

Centrifugal acceleration depends on rotational angular velocity (ω)

and the radius of rotation (r), i.e., a=ω2 r

Fc= m·ω2 r= m(2πn/60) 2·r

n is the number of revolutions per minute:

The amount of Fc is [g·cm/sec 2] (i.e. [dyne])

This is followed by the calculation of the relative centrifugal force (RCF).

RCF=Fc / Fg = m·ω2 r / m· g =ω2 r /g

g is the acceleration of the Earth's gravity (take g=980cm/sec 2)

Finally, the final conclusion is obtained in combination with the settlement coefficient.

V=2(D-d)gr2/9η

V is the sedimentation velocity of the particle, D is the density of the particle, d is the density of the solvent, η is the viscosity of the solvent, g is the gravitational constant, and r is the radius of the particle.

……

It can be used to isolate organelles from tissue homogenates, and the sedimentation order of their main cellular components is generally whole cells and cell debris first, followed by nuclei, chloroplasts, mitochondria, lysosomes, microsomes, and nucleosomes.

……

However, Chen Gong has fully grasped and memorized all the data.

So, it's enough to skip a lot of time and get straight to typing.

"Enter the centrifugal temperature!"

"Enter the centrifugation time!"

"Enter the centrifugal speed!"

……

Chen Gong chose density gradient centrifugation.

That is, according to the density of the nucleus, mitochondria, and particles, different gradients are selected.

This one is a bit more cumbersome.

Time passed like this, minute by minute.

The first time, 10 minutes later.

The tissue fluid homogenate is the first to isolate the nucleus, which is the cell that has not yet been destroyed.

After that, the supernatant needs to be selected and separated again.

But......

Just as Chen Gong continued to start, he suddenly heard a special sound coming from the separator.

The sound is not harsh, but ...... But it is clearly out of place.

To put it bluntly, this is the sound that appears when it is not working properly.

Examiners Liu Rong and Zhuang Baoshan are old qualifications, and they were judged at once......

This could be an instrument issue!

What to do?

Zhuang Baoshan was about to speak, but Liu Rong stopped him directly, looked at the other party anxiously, and signaled to relax.

Because of unexpected circumstances, it is also one of the components of the assessment.

And, most importantly, Chen Gong's previous performance was very good.

Half of the operation has been completed, and there are no problems with the follow-up methods and methods, including the details.

If there is no such contingency, it is obviously going to pass.

But......

Isn't the accident a pattern that exists in the lab?

As long as Chen Gong is calm and calm enough, who can deal with it in time according to the current situation, even if it is a power outage, or ...... If you choose other ways, as long as you meet the current scenario, you can give a good score.

As for replacing the device?

You can only wait for the next candidate.

Because even if Chen Gong changed the equipment at this time, he would not be able to complete the experiment.

Because half of the time has passed!

At this moment, Chen Gong was also obviously stunned.

He turned around and glanced at the two examiners, but ...... Seeing that the other party did not react at all.

This time, Chen Gong was a little curious!

This...... Is it also one of the contents of the assessment?

Chen Gong calmed down at this moment, he didn't hesitate at all, and directly turned off the power.

After waiting for the speed to stop completely, he said to the examiner:

"One of the common obstacles with the T-1055 ultracentrifuge is excessive noise."

"There is a special situation at the moment that requires the inspection of the instrument."

After speaking, Chen Gong directly turned on a switch that came with the back of the centrifuge, and a small device popped up.

Relying on a small wrench the size of a finger, Chen Gong could completely dismantle the instrument.

But......

Chen Gong didn't dare to waste time.

He still has an exam to continue.

So, he had to complete the experiment as soon as possible.

For a moment, he picked up the small wrench and quickly checked it.

"The centrifuge base is stable!"

"Centrifuge bearings are wear-free!"

"Centrifuge conveyor belt without relaxation ......"

……

At this time, Liu Rong and Zhuang Baoshan were dumbfounded.

They have been examiners for so many years, and it is not that they have not encountered a scene where a candidate encounters a machine failure.

It's just that...... I've seen the nervous, the panicked, and even the scared and crying.

But......

Or is it the first time I've seen someone who not only doesn't have any nervousness, but even tries to fix the machine?

For a while, even Zhuang Baoshan was a little overwhelmed.

He glanced at Liu Rong, and then really wanted to speak......

was stopped by Liu Rong.

Although Liu Rong is a woman, she is not in danger, otherwise she can become the female director of Dongshan Biochemistry Research Institute?

Without two brushes, why?!

Liu Rong knew very well at this time that rash interference would not change anything.

Chen Gong's behavior did not cause damage to the instrument.

Machines aren't that delicate.

Compared with the machine, Liu Rong wants to know what this child wants to do and what he can do!

The effect and value brought by a talent are far from being comparable to machines.

The machine is broken and can be repaired!

Talent buried? Nobody cares!

Liu Rong's face was serious, he didn't even take a step forward, he didn't say a word, he wanted to take a look...... What is this kid going to do?

She is willing to give Chen Gong enough right to make his own choice.

Deal......

What if she takes on this responsibility?

At this time, Chen Gong was still overhauling, and he didn't have much time left.

It's less than 8 minutes until the end.

Chen Gongshun disassembled the parts.

No aging and wear of the bearings were found, and no loosening of the internal parts was seen.

In this way......

Chen Gong's eyes suddenly lit up, right......

It could be caused by an imbalance in the centrifugal rotor!

Chen Gong hurriedly opened the internal rotor structure of the centrifuge, and sure enough, Chen Gong clearly saw that there were adherent samples on the rotor of the centrifuge!

Here's why.

As a general rule, the rotor of the centrifuge is cleaned regularly, and the rotor is cleaned and lubricated and sealed.

However, because of the assessment, it was also used yesterday, and during this time, long-term use was not dealt with in time.

As a result, condensate enters the centrifuge chamber and the rotor head, and if there is a leakage of the sample, adhesions are formed, resulting in an imbalance of the centrifugal rotor.

Although it seems to be only a slight change.

But......

In the working of ultracentrifuges, the rotor is the key, and a little load will lead to imbalance and noise.

Chen Gong hurriedly took out the neutral washing machine, wiped it slightly, then washed it with water, and then wiped it dry, and then installed it.

And at this time!

Time is running out......

After Chen Gong finished loading, there were only about five minutes left.

Chen Gong also hurriedly started the operation.

This time, he did not choose general density centrifugation.

Instead, differential centrifugation was chosen.

This is a method that uses different centrifugation speeds and centrifugation times to separate particles with different sedimentation speeds and different centrifugation times in batches at different centrifugation speeds and different centrifugation times.

Compared with the previous operation, the difficulty coefficient is higher, and the relative difficulty of control is higher.

However, two things can be done in batches.

Like what......

The precipitation was completed by low-speed centrifugation, and after collection, ultra-high-speed centrifugation was carried out to complete the secondary precipitation.

Moreover, Chen Gong used the technique of differential centrifugation, which can be used to separate the supernatant from the sediment by pouring after centrifugation, and can use an angle rotor with a large capacity.

Sure enough!

This time, Chen Gong directly chose to raise the rotor angle by 45 degrees!

And so it goes.

Although the wall effect is severe and particles can be extruded, it can be better separated and precipitated in a short time.

……

Liu Rong sat aside.

After listening to the crazy rotation of the centrifuge, there was no movement, and suddenly there was a little more excitement in his eyes!

And his follow-up operation made Liu Rong's palms clench.

She looked at Chen Gong, her eyes were full of excitement and appreciation!

What a brave and resourceful boy.

I came up with the idea of using differential centrifugation, and combined it with the idea of increasing the angle of the rotor.

This is really not the average person!

To be honest, Chen Gong's use of this ultra-high-speed rotor machine is simply beyond the level of ordinary experimenters.

Be bolder!

The road is wilder!

More fine-grained operation!

The mind is more active!

Chen Gong is more agile than those experimenters.

Even an intermediate experimenter would not have thought of doing such an operation in a matter of minutes.

They will give up in a serious way.

But......

The kid didn't do that.

Instead, it gives full play to the various functions of the machine.

It really surprised Liu Rong too much!

It's hard to believe that such an operation happened in the assessment of junior experimenters, and it was a ...... Assessment of the first-level introductory experimenter.

It's a bit unbelievable to say.

……

Soon!

Chen Gong finally completed the final operation before the time came.

Chen Gong wiped the sweat from his forehead, turned around, and bowed to the two teachers.

"Thank you, teachers!"

"I'm sorry!"

"I'm sorry for your trouble."

"But...... I propose to strengthen the maintenance of this T1055, his conveyor belt is not loose, but it is ...... I guess it's only seven or eight times, and there must be something wrong. ”

After Chen Gong finished speaking, he got up and left.

Zhuang Baoshan said to Liu Rong with a shocked face:

"Unbelievable!"

"This kid ...... Actually repaired centrifuges? ”

"It's an ultracentrifuge...... How daring! ”

"Not only was he not a little nervous at the time, but even the machine was fixed for him!"

"It's really terrifying!"

Liu Rong nodded, smiled slightly, and looked at Zhuang Baoshan:

"Director Zhuang, don't dare to be in a hurry when you encounter something in the future!"

"Look at it, young man, if you don't force him, he doesn't know how good he is!"

"You've seen the rest of the operation."

"Differential separation!"

"Zone effect!"

"Rotor adjustment."

"Double the difference in performance!"

“……”

"Do you think that a junior entry assessment person can have such strength?"

"Unbelievable!"

"I don't know what kind of teacher can train such students!"

"I was a little surprised."

Liu Rong had a little more envy in her eyes.

"If this child is in my hands, it won't take five years for me to make him the youngest experimental specialist in China!"

"It's just a piece of material that is born to do experiments!"

Liu Rong's praise is beyond words, and she is not stingy.

Zhuang Baoshan, who saw it, was a little crying and laughing.

"This kid, I haven't seen it before, it doesn't look big, it should be a graduate student, right?"

Liu Rong shook her head: "No! ”

"Definitely not a graduate student!"

"He doesn't have the stereotypical smell of graduate school."

"Definitely a college student!"

"Shanhe University ......"

"I don't know if I have an internship or not......"

Liu Rong shook her head, they couldn't see the candidate's information, so they could only give up.

"Alright, let's score!"

"yes, score ......"

"How?"

Liu Rong smiled slightly: "Except for a full score, I can't think of a second answer!" ”

After a while, Zhuang Baoshan looked at Liu Rong: "By the way, how did you write the evaluation?" ”

Liu Rong smiled: "Talented, with a tiger in his heart, the future is promising!" ”

"What about you?"

Zhuang Baoshan wanted to cover the scroll at this time, it was too embarrassing, look at what others wrote, how cultured they are, look at what they wrote......

"Instead of being nervous, the candidate tried to fix the machine......"

……

……

PS: First order: about 3000.

It's a passing grade.

For the results, starting from this book, it is still acceptable, after all, the threshold is relatively high, and the beginning is not in the hospital, and there is no use of what the veteran is good at.

However, people always need to change, and it is necessary to try to get out of the simple comfort zone and change the technique.

Take your time, I'm confident.

However, for a veteran writing career, hahahaha...... Not as high as the first book.

Ay......

It's all tears.

There are many reasons, and I don't summarize it, because thinking too much about this kind of thing affects motivation, so it's better to write this book well.

Still, ask for support!

Explosive change, it must be exploded, 16000 delivered, everyone is satisfied.

(End of chapter)