Chapter 300 - 204: Medical Titan

Chapter 300: Chapter 204: Medical Titan

Sun Changming was like a passing NPC who dropped a few harmless lines before making his own exit.

As for the "incompetent husband" part...

Chen Hao had to add, "I think I saw Professor Sun clutching his chest as he closed the door. You don’t think anything’s actually wrong, do you?"

Yi Xiangwan replied, "He’s fine. It’s probably just a little internal damage. He’ll be fine after a few days of rest. Let’s get back to work."

Chen Hao and Yi Xiangwan, landing a killing blow even after the guy had already left!

And it was Chen Hao who had just asked that question, every word a dagger to the heart, all while looking completely innocent.

’This Chen Hao, how can he be so wicked!’

...

They restarted the experiment.

The data sets on the NanoDrop were all perfect.

Wang Xiaoqing asked obediently, "Jiang He, what’s the next step?"

Although the current concentration and purity met the standards, the miRNA fragments were too short.

In a traditional reverse transcription experiment, an oligo(dT) primer is typically used to catch the Poly-A tail structure of the mRNA.

However, miRNA doesn’t have this long tail, so conventional reverse transcription primers can’t catch it at all.

Back in ’08, this was another technical challenge.

Labs all over the world were searching for an efficient and specific method to stably reverse transcribe these short fragments of just twenty-odd bases.

Jiang He said, "I’ve mentioned stem-loop primers before. Of course, the members who joined the group later wouldn’t know. Chen Hao, why don’t you give everyone a brief explanation."

"OK."

Chen Hao said, "This primer has two parts. The back is a stem-loop structure that forms by folding back on itself through self-complementation. Its purpose is to provide steric hindrance and increase stability. Sticking out from the front is a short segment, about six to eight bases long. This sequence is completely complementary to the 3’ end of the specific miRNA we want to capture."

Wang Xiaoqing nodded. "I get it. The few bases at the front of the primer first bind precisely with the tail of the miRNA. Then, the reverse transcriptase can use this double-stranded structure as a starting point and synthesize the complementary strand of the miRNA all the way through."

Yang Xu really wanted to jump in and show off.

But Jiang He hadn’t taught him this part yet.

He didn’t know it either.

He could only give up resentfully.

Chen Hao, on the other hand, felt great.

’—Who would’ve thought! The day has finally come when I get to lecture a professor!’

He smiled and continued:

"Not only that, but the stem-loop structure is folded and closed at room temperature. It only opens after binding to the target miRNA. This vastly decreases the probability of the primer binding to other, non-target RNA, causing the specificity to increase exponentially."

Lu Xiaolin added, "Right, the boss already designed the primer sequences. They just arrived this morning."

He pulled open a nearby drawer and took out a rack of centrifuge tubes from an ice box.

Jiang He glanced over, nodded, and said, "Now, prepare the reverse transcription system. Thirty minutes at 16 degrees for primer binding, thirty minutes at 42 degrees for reverse transcription, and finally, five minutes at 85 degrees to inactivate the enzyme."

"Roger that!"

「A little over an hour later.」

The reverse transcription program finished, and the enzyme was inactivated.

Next came the most nerve-wracking part: the validation stage.

It was time to run it on the machine—a qPCR (real-time quantitative PCR).

Everyone held their breath, quickly preparing the quantitative fluorescence system. They placed the eight-strip tube, filled with their hopes, into the ABI 7500 quantitative PCR machine on the side.

On the monitor, at the 18th cycle, the fluorescence signal suddenly exploded, tracing a perfectly smooth amplification curve!

A little over an hour later, all 40 amplification cycles were complete, and the machine entered its final heating stage.

The resulting melting curve that followed showed an exceptionally beautiful, single peak!

This meant...

Jiang He’s team had captured the miRNA with extreme precision and successfully reverse transcribed it!

A cheer erupted in the lab.

In fact, with the project having progressed this far, they could already publish a paper. This step alone was an incredible achievement!

The progress bar in Jiang He’s mind shot up another ten percentage points.

[miRNA Pancreatic Cancer Early Screening Project Progress: 45%...]

The technical bottleneck was broken.

Progress was advancing steadily.

Jiang He was very satisfied. He said, "Alright, the system works. All that’s left is repeated validation. Everyone take a break for twenty minutes."

Everyone started to relax and celebrate. Some rubbed their shoulders, others drank water.

Yi Xiangwan started telling one of her prized dwarf jokes, and Gu Yizhou couldn’t be bothered to react.

Zhou Yang and Lin Yue found a corner to review what had happened.

This was because they were both third-year undergraduates who had only recently joined the group and had a weaker foundation.

They couldn’t really get involved in many of the earlier steps, so they could only do odd jobs on the side and take notes.

Now that they had free time, Zhou Yang picked up a discarded pipette tip box to use as a teaching aid. He gesticulated as he quietly reviewed the process for Lin Yue:

"Look, that stem-loop thing the boss was talking about... my personal understanding, right? It’s like the lid of this box. Normally, it’s closed. But when it runs into that short miRNA—CLICK—it snaps shut on it, and then the enzyme just runs right along it..."

Lin Yue nodded like a chick pecking at grain. "Right, right."

Zhou Yang: "No, no, that’s a bad example. Let me try explaining it another way..."

Lin Yue continued to nod. "Right."

Jiang He sighed.

’Just as I thought. I never should have let these two join the group together.’

’Being forced to watch their PDA during an experiment... does this count as a workplace injury?’

Jiang He walked toward the door, his face expressionless. "I’m going to get some air."

Chen Hao: "I’ll go too."

Cheng Xiyao: "Restroom."

In less than half a minute, aside from the two people still in the corner murmuring "No, no," and "Right, right," everyone else had reached the evacuation point at the speed of light...

...

「The hallway.」

The night was dark and heavy.

Since everyone else was engaging in public displays of affection, Jiang He naturally thought of Teacher Shen.

He gave her a call.

But unexpectedly, the call was declined.

Then, a moment later, he received a text message.

[Little Clever]: Dr. Jiang, I’m at the library~

[Jiang He]: So late, and you’re still studying?

[Little Clever]: Yep, about to head back to my dorm now~