Live Journal Truth or Dare

[quesarah]

In her journal, mosca proposed a game of Truth or Dare.

The rules are:

TRUTH will be an open-ended question (i.e. not yes/no). It may be personal, or it may be about your opinion on something. Your answer may be any length, but it must be as honest as possible.

DARE will be a writing challenge of some kind. For writers of fiction, it will probably be a story challenge much like the ones you gave me in Total Request Livejournal. For people who don't want to write fanfic, I'll dare you to write a personal essay or review. Again, any length, as long as it completely fulfills the challenge.

I chose a nonfic dare.  Here is the dare she put to me and my answer.


The Dare:

Explain a scientific concept or process that you use regularly. Use language and style that would allow someone like me (high school science, math through single-variable calculus) to not only understand it, but find it interesting.

I make tools. Not tools made out of metal or wood, but chemical and biological tools. Our company sells these tools to biotech companies, pharmaceutical companies, government labs, and academic labs all across the globe. My job is to make tools that do a procedure called "quantitative RT-PCR." What the hell is that? Let me start with the basics.

When people talk about "genes" or "genetics" they're talking about the interrelationship between three types of chemicals: 1) DNA (deoxyribonucleic acid), 2) RNA (ribonucleic acid), and 3) proteins. As you may guess from the names, DNA and RNA are related. They are made up of four building blocks (abbreviated as A,T,G,C) in which all the information needed to make a worm, a gnat, a mouse, or a person is encoded. (Really, just 4 characters. I've always thought it was fucking brilliant that Nature is so concise.) The same information can be stored in either DNA or RNA, but they have different characteristics which allow them to do different tasks.

DNA is made of two strands of complementary material. All the genetic information is on one strand, but the other one is there to protect it from damage. Imagine a spiral staircase; two rungs going up the side for structural support, with the ATGC protected from damage in the center. This is great, like a fireproof cabinet for your genetic information, which in essence is what DNA is all about. One problem; DNA is cumbersome. In order to get at the genetic information, you have to unwind the spiral and then separate the two strands. This is where RNA comes in. It's like the speedy convertible of genetics, whereas DNA is the family minivan. RNA is a single-stranded chemical that carries only the most important information. It can move in and around a cell and take its information whever it's needed.

Which brings us to protein. The information carried by DNA and RNA most often needs to be translated into protein to be of any use whatsoever. Proteins are little biological machines; they do specific tasks, move things around, act as flags to bring other proteins over to do a job. They're worker bees. RNA will take the information necessary to make one particular protein into the cell, where other proteins do the translation. This is a neverending cycle. Machines wear out and break down and then RNA will bring out the information needed to make a replacement.

What does this have to do with "quantitative RT-PCR?" Glad you asked. Sometimes a researcher has a tube of something, blood or urine or sputum, and they want to know what's in it. Are there microbes? Viruses? What kind and how many? Quantitative PCR is a tool that's used for measuring the numbers of those organisms. It does so by targeting a piece of the organism's DNA and copying tiny stretches of it. The copies are tagged with a fluorescent chemical, the amount of fluorescence generated is measured, and then the fluorescence is correlated to the amount of DNA that was in the blood, urine, or what have you. Nifty, eh?

Now, there are certain reckless organisms, called RNA viruses, that don't care about protecting their genetic information by storing it as DNA. They care more about speed, stealth, and getting their proteins under construction as soon as possible. Remember, genetic information has to be in the form of RNA before it gets turned into protein machinery. If they skip the part where the DNA is unpackaged and transcribed into RNA, they're one step ahead of the game. And for these guys that means staying one step ahead of the immune system. For them, quantitative PCR has to be modified somewhat, so that their RNA information is changed into DNA information, which can then be measured in the manner I described previously. This is quantitative RT-PCR, and is what my tools are designed to do. Some veterinary science folks at UC Davis use them, some folks in local commercial labs use them, some folks at the CDC use them, and some folks at the Red Cross use them to screen blood.

So that's what I do. That's quantitative RT-PCR in a nutshell.
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Comments

[among-the-waves.livejournal.com]

how 'bout a dare? (I may not get to it for awhile b/c I am leaving tomorrow for a few days, but will eventually.)

[biogeekgrrl.livejournal.com]

How have your musical tastes changed over the years? What factors affected those changes? Do you think your taste has switched, or would you say it has broadened? Are there musical genres in which you'd like to be more educated?