Howdy all. My name is Matt Segal, and since my school requires all of its seniors to undertake 3 weeks of independent study as a graduation requirement, I’ve decided to spend my time working at the Rao Lab in the Immune Disease Institute in the Harvard Medical School. This is my second stint working at the lab (I completed a summer long internship last year here as well), and hopefully I’ll be able to give you a window into what real research lab work is like (at least to the extent that I’m able to experience it).

Riding on the crowded train and walking the short distance transported me back in time. It was as if nothing had really changed. All of the landmarks I remembered still stood, the courtyard was the same, even the woman who checked the ID badges was the same.

The first thing that I was told that I would be doing would be annealing some oligos we had ordered. Now, to first define the technical terms, an oligo is just a short section of DNA, and annealing is the process of joining two single strands of DNA into the better known double stranded version (since the oligos can only be ordered in single strands).

A gel run confirmed that the annealing worked, and, fortunately, there was no single stranded DNA left. Now, gels are probably one of the most useful tools in molecular biology. The way they work is basically by separating things by size. Little things can navigate the openings in the gel better than larger ones, which get stuck earlier. This size separation is very consistent, and different size strands of DNA or protein get clearly separated into different bands. Because you know what the size of your desired product will be, you can figure out whether it is actually present or not.

An agarose gel running (used for DNA). The long instruments near the power unit (which creates positive and negative poles in the gel, drawing the DNA, which is negative, towards the positive side) are called micropipettes. They let you measure small volumes of liquids (in micrometers, written as ul) very accurately.

A polyacrylamide gel used for proteins and stained using a dye called Coomassie Blue. In the column on the far left is a ladder – a solution that produces bands that represent known sizes, which allows you to compare the size of your protein. Here, each line (band) represents a different sized protein, and the thicker the band, the more protein of that size is present.

If you have any questions for comments, feel free to reach me at segal@idi.harvard.edu.