Playing the mad scientist

Today, I found out that I successfully mutated some DNA.

Not to do anything cool. Basically I have some cDNA for a gene that was sent to me by someone else, and it contained three mutations that make it different from the wild-type (normal) gene. This is a problem because it messes up the protein sequence that is made from this gene, which can screw up the protein's function. And considering I'm studying that protein's normal function in a cell, mutations are not cool.

So I had the task of mutating those three nucleic acids back to what they should be. It's not really as hard as it sounds, because a kit exists for it. What you do is order some short stretches of DNA which contain your desired mutation and that will sit down on the DNA sequence that you already have. You mix those with your DNA, along with an enzyme that synthesizes DNA from an existing copy and some free nucleotides, which are what the enzyme puts together to make the bigger pieces of DNA. Then you let the enzyme work its magic for a number of hours (this involves multiple temperature changes, but fortunately we have machines for that).

Once you have this replicated DNA, you get it into bacteria by opening pores in their cell membranes (by heat or electricity). Since the DNA forms a complete circle and contains all the elements necessary for more replication, the bacteria who uptake this DNA will produce more of it every time they divide. It's also possible to have multiple copies of your DNA in each bacterial cell. So then you grow the bacteria in food (we call it media) containing some sort of antibiotic, because the DNA you inserted into them also contains a resistance gene for that antibiotic. So only the bacteria containing your DNA will grow in the presence of this drug. Finally, you grow up a bunch of the surviving bacteria, extract lots of DNA from them, and send it to be sequenced. And hopefully you find that the resulting DNA contains your desired mutations.

All of that almost makes up for the fact that my right wrist strangely hurts today, in a sort of carpal tunnel kind of way. Repetitive motion injury from too much pipeting (aka moving around small volumes of liquid)? Ugh.