Autoclaves

The big autoclave at my work that can hold four trays worth of autoclave materials.
The big autoclave at my work that can hold four trays worth of autoclave materials.

I’ve mentioned autoclaves in my science posts in the past. Autoclaves are one of the basic sterilization tools in a lab.

The autoclave pictured above is one of the bigger ones around used by the people in my rice lab.

What is an autoclave? Basically a its a steam oven.

When scientists were first trying to sterilize stuff, boiling a solution on a stove was the easiest way.

But boiling has a problem.

Say you want to create a solution of 3 liters of water with 4 grams of salt per liter. You measure out 3 liters of water and you pour in 12 grams of salt.

But now you need to sterilize it. You put it on the stove to boil.

After it boils you measure the volume of your solution and now only 2.5 liters are left!

So the solution is sterile, but its no longer the concentration you wanted.

There are ways to work around this obviously by adding more water or less salt, but that gets tiresome.

Eventually a French scientist, Charles Chamberland, invented the autoclave to avoid this sort of problem.

The temperature inside an autoclave heats up to 121°C (250°F). This is a higher temperature than boiling.

Normally water would boil in an autoclave and you’d have the same problem, but heating isn’t the only thing an autoclave does.

The air pressure inside is about 20 times room pressure. This air pressure forces the liquids you place in an autoclave to stay liquid instead of evaporating into gas.

Thus the temperature can be raised to kill any bacteria, microbes, or other nasty things in your solution of salt water, but the solution does not changed its concentration.

The most interesting part for me is why the machine is called an autoclave.

Autoclave is a Greco-Latin word that means self-locking.

With a normal oven you can open it at 250°F (121°C) and you’ll be fine.

But what if that oven was full of 20 times the amount of steam that normally would be in there?

The steam would fly out of the oven and give you horrible burns if the autoclave was opened suddenly.

Thus it was very important for Chamberland to prevent that accident.

The autoclave cannot be opened until the steam has been condensed into water and removed from the machine. The bottom left of the picture on this blog shows the pipe where the hot water comes out of the autoclave.

That’s all for today!

-Mister Ed

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Disposing of GMOs

The rice we grow in one of my lab's greenhouses.
The rice we grow in one of my lab’s greenhouses.

Yesterday I was working out at the greenhouse for my rice genetics lab.

I was getting rid of some old rice plants that we’d collected the seed from and no longer needed.

If a plant got to this point in a garden you’d normally throw it in the compost so it would be useful next year.

That’s not allowed for the rice we work with in my lab because it is an untested transgenic line.

Some members of the public dislike altering the genetics of food crops to create genetically modified organisms (GMOs). There are a couple of logical reasons for this and a couple of illogical ones.

Logical reasons include: religious objection, lack of crop diversification, cross-species allergens, and the strengthening of agribusiness monopolies that often accompanies GMO crop use.

Illogical reasons often have something to do with safety or not knowing what is in a product when you purchase it at the grocery store.

I could go on about this a lot. GMOs are a complex topic with a lot of ground to cover, but that wasn’t why I was writing this post today.

Because of the fear of GMOs, they need to go through extensive testing before they are declared legally safe. This testing can take up to ten years.

We don’t do that for every strain of modified rice in our lab, so certain precautions need to be taken.

Yesterday I cut off all the excess seeds on the old rice plants. The seeds go into a plastic bag.

The seed bag and the leftover portion you can see above both go into an orange dumpster at the center of the greenhouse complex.

All the stuff in the orange dumpster then goes into a special oven that ensures the modified crops won’t somehow get into the wild and start growing there.

After the special oven, called an autoclave, has destroyed the genetic material in the rice it can go into a normal dumpster or be used for compost.

Just another little glimpse at my job!

-Mister Ed