Abandoned Lab

Two shelves I filled up with pipette tips.
Two shelves I filled up with pipette tips.

Last week the rice research lab I work in was all but abandoned due to a local conference on plant pathogens.

I didn’t go to the conference as I’ll soon be changing to working entirely on C. elegans.

Spending the lab’s money on me learning more about a topic that I probably won’t encounter again would’ve made me feel guilty.

I was left in the lab with a few people who stayed behind or came back early.

I finished all my usual duties in the lab like taking care of plants and setting up stuff for next week, but I still had a lot of extra time before the end of the day.

I cleaned up the lab a bit and… FILLED TIPS.

I filled two entire shelves with boxes of tips.

You might be wondering what are tips and what are they used for?

Biological research often requires very small amounts of liquid to be measured.

For comparison, in the science we usually measure volumes of liquids in liters.

Most people are familiar with liters in the form of those two liter soda bottles that are used for parties.

A milliliter is equal to one thousandth of a liter, or two thousandths of a soda bottle.

A milliliter is still rather big though. It’s about the size of the last joint on your pinky finger.

The research I perform measures liquids in microliters, which are one thousandth of a milliliter (or two millionths of a soda bottle).

A microliter is about as big as a period.

So how is something that small measured?

With a pipette!

A pipette is essentially a mechanical suction device, similar to a straw.

A pipette tip is added on to the sharp end of the device you see above.

The button on top is pressed down, expelling a specific volume of air from the pipette.

When the button is released the pipette sucks that volume back up into the pipette tip.

Pretty much the same principle as using a straw to drink a two-liter bottle of soda.

The amount of air expelled from a pipette allows researchers like me to work with extremely small volumes. Some pipettes can even measure volumes as small as a thousandth of a micoliter (Another name for that is a nanoliter).

When working with small volumes like this its even more important to be clean.

Any small contaminant on the pipette tip would be a large contaminant in a mixture of only a few microliters.

So the tips are put into those boxes in the first picture and then autoclaved to sterilize them.

Oh and here’s a closeup of a pipette tip!

-Mister Ed

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