Wait - I Do Science Too

August 26, 2011

Rheanna Sand


Typically, in this spot every Friday, you will see a few hastily assembled paragraphs about the latest cool thing launched into space, or about a new miracle drug, or, lately, bats. But this week is different. This week, my very first scientific paper was published in the Journal of Experimental Biology. But if you're hoping I'm going to blog about my own paper, think again! I've written SOOO many words about jellyfish Kv3 proteins that just typing that made me cry a little.

No, what I was thinking was a little experiment in live blogging. I am, after all, in the midst of what some people call "playing God." Not Craig Venter-style creating artificial life, but altering the molecule of life, DNA or deoxyribonucleic acid. DNA is a long string of chemicals that are interpreted like a code by proteins to make other proteins. All life forms share the same code, and discovering this fact created the entire field of molecular biology that we know and love today.

Knowing the code + Knowing how to introduce tiny changes into the code = PLAYING GOD

This is what me and other protein scientists do before the "real" work begins. We make the DNA read exactly how we want it to. So how does this relate to my work? I'm taking a protein from a mouse (called Kv1.2) and changing the code in two separate places. Why? I think I know where a snail toxin is binding and I want to mess with those regions to see if it messes with the ability of the toxin to mess with the protein. I know, it's messy.

So, this playing God thing happens in a few steps. I make the changes in the DNA in a tiny tube filled with starting materials, a protein called polymerase that replicates the DNA, and other "fertilizers" that make the reaction go.



I do this reaction (called a PCR) a few times, and after every time I put the DNA in a gel (jelly) that separates it out by size. Then I can cut out the "bands" I want and play with them some more. In the end I hope to have pieces of DNA that are changed exactly how I want them to be. Then they will be created into the messed up proteins I want them to be. It's like practice for parenting!

Okay, so, let's see some results. The first reaction, expecting 10 bright bands:

FTW? Only one band? That makes no sense. Perhaps I should try it again, but this time spinning around in a circle and tapping my left foot three times before loading the tubes:


VOILA. 10 bright bands. Excellent. The second reaction, expecting 5 bright bands:



Hmm… multiple bands. Things are usually great in multiples, except in PCR. I cut out the top bands (bigger = better, duh) and re-did the PCR…. Last night. Now, I'm waiting for my gel results…




Update (2:00pm): The results are in - and as usual, there is at least one that is giving me trouble. I expected to see one bright band in each of the lanes, but instead saw multiple bands! Plus the first two lanes (after the DNA ladder) have only weak bands at the right size. But, 4/5 ain't bad (each sample was loaded into 2 lanes, so 5 in total).



So, moving along... I cut out the top bright bands from all of the lanes and cast a magic spell to release the DNA. Now the DNA is getting chewed up by special proteins called restriction enzymes. The enzymes make "sticky ends" that can be glued back together to create mutant DNA . That is, if the reaction works... we shall see...


Update (8:51pm): The reaction was a success! But, as is the rule in molecular biology, I still had to repeat it. There just wasn't enough DNA in the first run. A lot of DNA is sacrificed when playing God, so you have to give yourself plenty to work with. Anyway, I re-did the reaction with three times the volume of starting material. It worked beautifully.


So much so that I forgot to upload the picture! Guess you'll just have to wait until next week!



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