Thread by @lesliekulot

#COVID19 Testing Made Simple: A Thread

Hello friends, I finally finished it! ☺️ A lot of these are really technical but I tried to make this as simple as possible, inserting key molbio concepts every now and then. Let’s learn something new today ✨ #SciComm

Let’s break it down into FIVE steps, one tweet per step.

1. Sampling & Extraction
2. Primer & Targets
3. Processing
4. Results
5. Errors

Before we start, take time to learn the central dogma of molecular biology first. Move on when you feel you have an idea of the concept 🧬

1️⃣Sampling & Extraction

Our goal is to collect viral samples and to obtain RNA. This is like sweeping… you get everything that is found in the sampling area. 🧹

2️⃣Primer & Targets

Getting tricky! How do we select and detect the SARS-CoV-2 RNA from that tube of… stuff?

To understand this, we need to discuss two concepts:
🔎Primers - used to find “snippets” of a target gene
📄Targets - gene that we are looking for

3️⃣Processing

So far so good? More technical stuff ahead!

To find out if the sample has the virus, basically, we run the primer & patient sample in a machine to see if the sample has this “snippet” which indicates the presence of the viral gene target. How does this happen? 🧬

4️⃣Results

Stay with me!! This is crucial 😅

To say that the TARGET (SARS-CoV-2) is present in the SAMPLE (NP swab), I must reach a certain threshold 🖥

This is quite complex. To simplify, if it reaches the threshold, then I’m QUITE confident that I have the virus: COVID➕

5️⃣Errors

But quite confident only? Why not FULLY confident?

Because no test is perfect. This is where errors enter. One type of error would be having a false negative — to test negative even though you really have the disease 📣‼️

To end this thread, I will discuss why is testing important. #MassTestingNow

I'm not claiming to be an expert, so I'm open to your comments and corrections! I hope you learned something new today! Stay healthy, everyone ✨ #COVID19

The write up is here as well. Filipino version coming up soon! ☺️📖

lesliecando.wordpress.com/2020/03/26/sim…