Liquid Nitrogen in the Lab

A thermos with some bubbling liquid nitrogen at the bottom.
A thermos with some bubbling liquid nitrogen at the bottom.

Liquid nitrogen is used pretty much everyday by someone in my lab.

Liquid nitrogen is an extremely cold liquid coming in at close to -200°C (-330°F).

Nitrogen’s natural phase is a gas. Its a fairly common gas to, making up 78% of the Earth’s air.

When it nitrogen is condensed as a liquid it is essentially always at boiling temperature.

I tried to capture the vapor coming off the bubbling liquid nitrogen in the picture above, but its difficult to convey what liquid nitrogen is like in a photo.

Liquid nitrogen looks exactly like boiling water. If you put liquid nitrogen into a pot it would look just like a boiling pot of water ready for spaghetti to be added.

But liquid nitrogen is not boiling water. It won’t scald your hand if you touch it.

Liquid nitrogen is the coldest thing you will ever touch and can instantly freeze burn your hand.

Even things that come out of liquid nitrogen are painful to touch with you hands. I can’t do it for more than a second.

Using gloves to handle liquid nitrogen has another problem attached to it.

When you wear gloves a natural layer of sweat and oil occurs between your hand and the inside of the glove.

If your gloved hand is in the liquid nitrogen for too long, the sweat freezes.

That’s just ice though. It’s happened to me plenty of times. I just yank my hand out of the nitrogen and my bodyheat melts the ice back into sweat right away.

So if its so dangerous, why do we use it in the lab?

Liquid nitrogen is useful because it stops all biological activity. That’s why its dangerous and why its useful at the same time.

When working with a dead specimen its best to prevent bacterial decay. Bacteria can’t survive at liquid nitrogen temperatures, so its used for that.

Liquid nitrogen is also used to isolate RNA from a specimen.

Every cell has RNA inside of it, but RNA is also what many viruses are made out of.

Cells quickly learn to distinguish RNA inside the cell as good and RNA outside of the cell as bad virus RNA.

Cells have defense mechanisms to destroy RNA called RNases.

RNases can’t work at liquid nitrogen temperatures though!

I was using liquid nitrogen for a third purpose today, just to quickly freeze some worms.

More on why I need to freeze worms another day!

-Mister Ed

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Worms and Introns

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I have two jobs right now. One of them is an internship working on introns.

Introns are part of your genes, but they’re a strange part.

Imagine your genes are like a TV show. There are parts you watch and there are the commercials that you mute or ignore.

When the TV show comes out on DVD or Netflix the commercials are removed.

Genes are split up into watchable parts and commercials too. The watchable parts are called exons and the commercials are called introns.

When DNA makes RNA the introns are removed from the code, just like when a TV show is released on DVD the commercials are removed.

For a while scientists thought that introns did nothing for the genetic code of an organism. Introns were just useless DNA trash.

That changed in the late 1980s when some introns were found to enhance the expression of genes.

Some genes have what are called enhancing introns that increase the expression of that gene. This is called intron mediated enhancement (IME).

If you take an enhancing intron from one gene and put it into another, then the other gene will create more RNA and thus more proteins as well.

So enhancing introns increase expression of a gene, but not much is known about why. The lab I work in is one of the few that studies this process to try and figure out the specifics.

Most intron research right now is done in plants. I’m trying to extend that research to animals by using worms.

The worms I use are called C. elegans. They’re only 1mm long and are commonly used for research projects around the globe.

My lab previously discovered that enhancing introns in plants work best near the beginning of a gene.

My project is to see if the same holds true for C. elegans.

I’ll also be looking at whether an intron that is enhancing in plants is also enhancing when out into a gene in C. elegans.

That’s all for now!

-Mister Ed

What Is My Profession?

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I’ve talked about how I work in a lab before, but haven’t gone into specifics.

There’s a bit of background knowledge needed before you can fully understand what I do at my job though.

I work in a research lab which means I’m a scientist. What type of scientist am I? A biologist!

Biology used to be all about plants and animals and stuff, but since the discovery of DNA that’s changed quite a bit.

Studying animals and plants is now referred to as zoology, botany, or ecology.

Biology now almost exclusively refers the study of DNA and other things related to DNA.

You probably remember learning about DNA in school where your teachers described it as the “instruction manual for your body” or something to that effect.

That’s essentially true. DNA does provide the instructions for building everything in your body. But how does it do that?

DNA is kept inside a protective bubble in your cells called the nucleus. When an invader like bacteria or viruses gets into your cells they are cut off from your DNA by the nucleus.

If invaders could get at your DNA they could alter it. These alterations are what make viruses so dangerous. Alterations can also cause cancer.

But with your DNA cut off from the rest of your cell how does it provide instructions?

DNA produces a copy of its instructions called RNA that leaves the nucleus.

RNA goes to something in your cells called a ribosome.

Ribosomes read the instructions from RNA and create proteins.

This is where I got a little confused in my biology classes. Aren’t proteins just one of those things on the nutrition facts labels?

Turns out proteins are responsible for almost all cellular activity your body performs.

Proteins make your cells move, send signals between cells, help your cells digest things, etc. They do everything.

So the whole process is DNA makes RNA which goes to ribosomes which make proteins. Proteins then go on to do everything else.

In both my labs I study the first step, the organization of DNA and how RNA is made from it.

I’ll tell more about each of my labs in a future post.

-Mister Ed