She’s Crafty

Coronavirus testing and how it works is not something most of us understand. Reading about it requires sifting through all sorts of sciency mumbo jumbo. Which can be hard. Especially, if you aren’t a science major. I suppose it helps that I got myself a science major once upon a time and have spent the last 15 or so years teaching. To begin with let me lay out a tiny bit of science.

Coronaviruses, influenzas, and a whole host of other viruses are composed of RNA. You’ve all seen the little blue balls with red tufts. That’s just a marketing campaign’s simplification of the real thing. It’s not even blue and red. (3) Understanding how it’s actually made out of RNA is quite a bit more complicated and involves our imagination as even with all the scientific equipment in the world, we can’t actually see the even-smaller-than-microscopic nucleotides fit together to make the iconic “blue ball”. (Scanning electron microscope images here (4))

RNA like DNA uses nucleotides like building blocks. The nucleotides form nucleic acids. There are 5 of them, commonly referred to as A, T, U, C, and G. RNA utilizes only four nucleic acids, A, U, G and C. (6) It’s the way that these are put together that creates things. That’s what Covid-19 tests are looking for, a specific way that the A’s, U’s, G’ and C’s are put together that is unique the RNA virus, Sars-Cov2. The test however, isn’t looking for the entire RNA sequence that defines Covid-19. It’s only looking for some of it, a “virus fragment” (5).

The two most common tests used in my neck of the woods are the RT-PCR test and the Rapid Test. Sounds kinda like the same thing. Right? Well, they’re not.

The RT-PCR test is technically the Real Time Polymerase Chain Reaction test. The Rapid Test, is just the Rapid Test. Both look for pieces of RNA in whatever random bits can be found up your nose. To understand both, we are going to break out mom’s craft supplies. We’re going to do a crafty, elementary-schooly, experimental recreation of the Rapid Test and RT-PCR test.

I have represented the five nucleic acids with five letters. Yet, instead of A, T, U, G, & C, there are C, O, V, I, and D. Pulling out my handy dandy elementary school scissors and a stack of craft paper. I cut out 64 of each letter, found a “giant q-tip” and a “nose”. Let’s begin.

RT-PCR test and the Rapid test step #1:
The “giant q-tip”:

Rapid Test and RT-PCR test step #2:
Stick the “giant q-tip” up the “nose”
(The Rapid Test doesn’t actually have a giant medical stick. It’s just a pretty regular q-tip-y thing.):

Yes, that 5 gallon bucket is our nose stand in

Remember the RT-PCR test and the Rapid Test are looking for a sequence and we are too. We are going to look and see if we can find a specific sequence. If the sequence C-O-V-I-D can be found, our crafty test will be positive.

RT-PCR test and the Rapid test step #3:
Here’s what came out of our “nose.” For this step I held the five letters above my head and let go. This is how they fell on the floor. Can we find the specific sequence we’re looking for? The test will be positive if the random sequence C-O-V-I-D can be found.

Even though C, O, V, I and D, are present, the sequence is not. The Rapid Test stops here. The sequence C-O-V-I-D was not found. Test negative.

here’s a negative test most are familiar with

RT-PCR test step #4:
Using major technology, make a copy, look again. There are now 2 C’s, O’s, V’s, I’s and D’s:

No sequence C-O-V-I-D found.

RT-PCR test step #5:
Make a copy, look again. Now there are 4 C’s, O’s, V’s, I’s and D’s:

the “test” is still negative, the sequence is not found

Our test continues being negative, so the RT-PCR keeps going. Step #6 gives us 8 copies. Step#7 and there are 16 copies. Step #8 and there are 32 of each letter.

RT-PCR test step #9:
Make a copy, look again. Now there are 64 C’s, O’s, V’s, I’s, and D’s. I had help randomly sprinkling them about. With four people letting letters flit from their hands approximately six feet in the air and drift slowly to the floor, there was no way I could control the results. And no way for me to cheat. Well, I suppose I could have but my helpers would have cried foul. It wouldn’t be much of an experiment if I put the letters on the floor where I wanted them. Can you find the sequence C-O-V-I-D?

64 copies, in RT-PCR terminology this is the equivalent of cycle 6

Well, my three helpers and I did:

I know… super sophisticated. Hey, I am just a mom. The resources at my disposal include scissors, paper and well.. that’s about it.

Despite the technologically vacant methodology here, I think we can see that there are obvious differences between the Rapid Test and the RT-PCR test. Here in the Peace Garden state we’ve been utilizing a system that allows for 45 copying events, “cycles” is the correct PCR term. This gives 7,680 copies of the original. Imagine what that floor above would look like with 7,680 C’s, O’s, V’s, I’s and D’s on it. What are the chances a C-O-V-I-D sequence could be found? Probably pretty high. We’d likely find many of them actually.

The Rapid Test is known for having a high rate of false negatives. Which means that you could have Covid-19 but test negative. The RT-PCR test is known for having a false positive rate up to 75%. That means that 3 out of 4 people who test positive for Covid-19 using the RT-PCR test don’t actually have it. (1) Even Dr. Fauci agrees that an RT-PCR test which needs “20 cycles” to test positive, does not mean the person has coronavirus. “It’s just dead nucleotides.” (2)

If you really want to know the details, with out reference to elementary-school-esque crafts, then go here: https://www.sciencenewsforstudents.org/article/explainer-how-pcr-works or here: https://www.zerohedge.com/medical/covid-19-rt-pcr-test-how-mislead-all-humanity-accepting-societal-lock-downs

(1) Department of Epidemiology, School of Public Health, Xian China