Monday, June 27, 2005

Tools of the Trade

Particular to each lab project is a set of tools that can only be represented as drawings, such as a scheme to describe the two-hybrid method and the vectors used in this particular project, like the pACT2 vector, shown below:

This vector is used to create a fusion protein between your protein of choice, cloned into the multiple cloning site (MCS), and the GAL4 activation domain (in orange). It also contains genes for auxotrphy on -Leucine media and resistance to ampicillin (both in light orange).

While this sort of tool is the most interesting part of the story to our fellow scientists, the non-scientists of the world are more interested in tangible tools. So here I present them:

Here we see the common equipment housed at the end of my bench. Everyone in the lab has access to these, and everyone has some kind of common equipment on their bench. On the left is the clinical centrifuge, which spins up to 50ml of liquid about 3000rpm, or 2200xg (2200 times the force of gravity). That's slow.

The next is a centrifuge, which spins up to 1.5ml of liquid, at speeds up to 13,000rpm, or 16,000xg. That's fast. Both are used to pellet things, like yeast or bacteria, which grow in liquid culture.

Next is the water bath, for incubating things at temperatures from 25-50 degrees C (that's about room temperature up to the temperature of hot bath water).

The rightmost object is actually a hybridization oven (or hybe oven, for short), into which you can place a glass tube that will be slowly turned so that whatever is inside the tube (usually a radioactive membrane, hence the tape) will be continually and evenly washed in a liquid at a set temperature. These are expensive and excellent contraptions, but this one is instead being used as a benchtop incubator (something much cheaper and less specialized). Because we can set it to any temperature, it is good for incubating things (yeast plates) at a different temperature than normal. This one is at 37 degrees (body temperature), because the regular 37 degree incubator seems to kill our yeast. Dunno.

On the left here is another hybe oven, this time bigger and being used for its intended purpose. The two shakers are to the left of it. The shaker on the right (white) tilts like a see-saw, while the shaker on the left rotates like the teacups at Disneyland, but without the spin element. Both are being used to evenly wash membranes at room temperature. Not pictured: the nutator, which rotates like a see-saw on two axes, and has a funny name.

Everyone has a radiation station, but not everybody's is quite this cluttered. It consists of a plexiglass shield (center), a solid waste container (right, rear), and a "sharps" waste container (left, red), on top of many layers of benchcoat, also known as diaper (blue edges). Also shown are a liquid waste bottle (big radioactive label), two hybe tubes (behind the shield), which go in the hybe oven, and a geiger counter (left, brown), for measuring radioactive emissions.

Pictured here is perhaps my favorite piece of equipment: the PCR machine, or thermocycler. The discolored yellow/brown thing on top holds 96 tiny tubes, in which we mix DNA and other . . . stuff . . . and then we close the lid, turn on the machine, and update our blogs for 3-4 hours, while the machine cycles through three temperatures 25-35 times. The first PCR machine was an undergrad with three water baths and a timer. Some people would say that PCR was the most important invention of the 20th century.

And finally, perhaps the most important tool of the biochemist is the most basic: the pipetman. Shown here with his box of blue tips, this pipetman is like a turkey baster, but much more accurate and for much smaller volumes. This one can pipet 0.2 to 1.0 ml. (1 ml is equal to 1 cubic centimeter, and 1 ml of water weighs 1 gram.) We have one pipetman that can pipet as little as 0.5 microliters. Just to give you an idea of that volume, one "drop" of water is about 50 microliters.

I hope you've enjoyed my little lab tour.

1 comment:

  1. Yay! You know I'm totally jealous of your lab. Thanks for the tour!

    Hee. Nutator. Are you sure it doesn't mutate... nuts... into... something else? Hee.

    I especially like the fast centrifuge. I saw a thingy once where they spun a cornstarch solution at hyperfast speeds and poked a little hole in the surface of the liquid, which then started growing weird fingerlike protrusions. And waving them about. Do you know what that's all about?