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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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

Acceptance Wall

Normally I’d post something about D&D on Monday, but this week I’ll be showing off something that came in the mail recently.

My first graduate school acceptance letter.
My first graduate school acceptance letter.

I got into graduate school! Hurray! Validation!

This year I only applied to local schools as my wife is in the first year of a two year program for her teaching credential.

I applied to two programs at the college I got my undergraduate degree from and a third program at a nearby CSU (Sac State).

I’ve been rejected from one of the programs and have yet to hear back from the other one, but Sac State has accepted me! Woohoo!

Assuming the other program doesn’t accept me, I will be driving to the capital every day to learn and research science stuff.

The professor I’ve been placed with studies salmonella. I haven’t read up a lot on it, but what I saw on the papers she’s published was interesting.

Salmonella typically hurt your body in many ways one of which is by attacking your macrophage cells. Macrophages are the part of your immune system that eats bacterial invaders.

The salmonella bacteria don’t like being eaten by macrophages though. They protect themselves by putting poisons into your macrophages.

The professor has helped discover how this process works and she is attempting to harness the power of salmonella for good, not evil!

You see, if salmonella are so good at invading macrophages and killing them, they can also be used to invade macrophages and help them.

We can modify salmonella to make it deliver medicine to macrophages. This could do a number of things.

It could protect against auto-immune diseases like HIV. It could also super charge the immune system to assist the fight against other bacterial infections. These two things are some of the most sought after effects in medicine right now.

HIV is a huge problem throughout the developing world, so the interest in that is obvious.

The second effect, of boosting the immune system is even more amazing in my opinion.

Bacterial infections such as tuberculosis, STIs, and many others are currently treated with antibiotics. But bacteria can evolve and become immune to these antibiotics.

Researchers can come up with new antibiotics, but in a few years the disease will have evolved immunity to it again.

But what if you treated the disease just by making the immune system better? The bacteria can still evolve past this, but it takes much longer to do that than to develop antibiotic resistance. Possibly long enough that the disease can be eradicated entirely? That would be astounding.

While my original goal was to get entrance into a PhD program, working on making people immune to disease doesn’t sound that bad either. I think I’ll be quite happy at Sac State.

That’s all for tonight!

-Mister Ed