Cool Science: DNA Fingerprinting

It's kind of weird, but one of my dream jobs (I have many, ranging from stationery designer to CEO. #casual.) would be to work as a medical examiner. Okay, just hold up a sec and actually think about it. Just ignore the dead bodies for a minute and it's actually a super cool job. You get to work with crime and the police department, you get to work with the justice system, you get to work with science. A perfect fit for me! Plus I probably would have a bad bedside manner because I'm grumpy in the mornings. No need for a good bedside manner with dead people! Too far? Sorry.

But I do think the crossroads of science and justice can be really, really interesting, especially for a casual scientist. One common scientific procedure in crime (at least according to Law & Order SVU, which may or may not be my main source for this post) is DNA fingerprinting. 

The science of fingerprinting and classifying finger prints is called dactyloscopy, and I'm really only telling you that because it's a cool word and you can feel intellectual if you casually mention it in conversation. But the actual process of connecting a fingerprint with DNA (your genetic ID) is called electrophoresis. 

Electrophoresis takes place in a bunch of steps. First, DNA is isolated and basically cut in half. Then, little chemicals called restriction enzymes cut up the DNA at certain spots, making a bunch of segments of different sizes. The restriction enzymes cut every person's DNA at different places, making the lengths of segments different in every person.

These segments of DNA are called RFLPs (restriction fragment length polymorphisms)...but they are pronounced like "riff-flips", which is sort of fun. So these RFLPs are put in a gel and a charge is sent through the gel, which makes the RFLPs sort themselves by size. Once dyed, these give a display that can be compared against someone's DNA in a data base. It looks like this.

This chart can also be used to tell someone's maternity or paternity. Each of a person's lines (which represent a RFLP, a segment of DNA) is identical to either their mother's or father's. 

If you're interested in learning more about DNA fingerprinting, here are a few resources:

• DNA Fingerprinting
• A game where you can simulate gel electrophoresis
• More basic info on how it works + applications.

How interesting is forensic science?! And how will you use dactyloscopy and RFLPs in a conversation today?

P.S. My favorite recent science articles and why science means we might replace streetlamps with glowing trees #nbd.

living for the weekdays + free wallpaper + something new

Hello friends! Happy Tuesday! Or almost happy Wednesday if you live in my part of the world. Usually on Wednesdays, my thoughts tend to sound something like this: "Still three more days until the weekend."

But I'm making an attempt at being positive by telling myself that my weekdays are not something to race through or get done with, even if it seems that way sometimes (/all of the time, ever). So I'm trying to focus on the potential that my weekdays have. My weekdays generally consist of classes, homework, tutoring and if it's a good day, exercise.

Instead of "still three more days", I'm trying this:

• I have three more days this week to ace tests.


• I have three more days this week to help a kid hate math less.


• I have three more days this week to make someone's day a little less stressful.


• I have three more days this week to do something fantastic.

When I focus on it that way, I find that I'm excited for tomorrow, because I can do great things with it. I can succeed in my school work and lighten someone else's load and just generally cheer other up with my witty words and stunning good looks.

Because if we're really just living for the weekend, then we're not living for much at all.

As always, I like to remind myself that my happiness is my choice (I figure if I keep telling myself that, eventually I'll remember it). So this is my new iPhone background. I invite you to use it as yours or share it however you want. Just click on the iPhone to download.

And nowwww, I want to try something new. Last week, I posted about science for the first time (not counting Marie Curie). I was really nervous about it, since it's not really a "blog-friendly" topic, if you will. But I got a lot of good feedback--lots of people said they loved it even if they didn't love science. And they loved that I was posting something that I wanted to, just because it's me. And I do want my blog to be "for me", as I think all lifestyle bloggers do. But I also want it to be read.

So I'm testing out a new idea to kind of integrate science into other posts. I will still have regular science posts (I think), but infrequently. Instead, I'll add a paragraph or two at the bottom of regular posts about science, whether it's something I've learned recently, something in the news or a video. I hope you'll find these little science bits interesting but not overwhelming if you're not into it! As always, please let me know how you like it.

Science Bit of the Day

The other day I heard a fascinating story on NPR about a neuroscientist named James Fallon who had studied the brains of psychopaths for many years. At a family dinner, Fallon's mom mentioned that he should look into his dad's family history. So he did, only to find that his own lineage was full of murderers and other criminals. He convinced his family to undergo PET brain scans so he could compare their brain activities to those of psychopaths. He found that all of their brains were normal (aka they weren't serial killers) but found a terrifying discovery within his own brain. Want to find out? Listen or read the story here.