Going Bananas

BANANA EXTRACT: Today we stumbled upon Scientific American's "Bring Science Home" series. What a wonderful discovery for us!  A STEM-related Facebook post pointed is to a step-by-step set of instructions about how to extract DNA from a banana. How fun does that sound? You had to know we were going to try it!

The first step was placing a bottle of rubbing alcohol in the freezer while we prepped our bananas. Next, the bananas were peeled and then placed in Ziploc bags.  

The kids used their fingers to smoosh the bananas into a pudding like consistency, with no lumps remaining. 

Then, it was time to fill a measuring cup with a half cup of water and a teaspoon of salt. (We doubled that, because the kids were each doing their own banana.)

The saltwater was poured into the bag, and the bag was resealed. They then gently mixed the saltwater and the mashed banana together for about 45 seconds. 

Next, it was time to add a half teaspoon of dish-washing detergent to each of their bags, and then they mixed them gently again, taking care not to make it become too foamy.

We topped two narrow glasses with coffee filters, and they carefully poured their banana mash into the filters.

They watched as much of the liquid oozed down into their classes. After about six minutes, we removed the filters from the tops, and our glasses looked like this. ...

They each had an inch plus of cloudy liquid on the bottom.  It was time to take the rubbing alcohol from the freezer. The kids each carefully added an inch-plus of rubbing alcohol atop the cloudy banana extract. They did so slowly, to keep the liquid layers as separate as possible. Here, you can see the clear liquid atop the cloudy.

The instructions said to wait 8 minutes and watch what was happening. We did just that.  We started to notice bubbles and some kind of stringy substance forming between the layers.

Our instructions told us this area between the clear and cloudy was where the DNA pieces were clumping together!

When our 8-minute timer rang, the kids stuck wooden craft (Popsicle) sticks into the cup and spun them in place, per instruction, trying to capture some of the stringy middle layer. 
They each successfully did so, and were thrilled to see banana DNA on their sticks!

We even added a little color to the mix to try to see glass' contents better.

How cool is that?! Now that we have mastered banana DNA extraction, our next project will be creating a Frankenanner! (I think we need to trademark that name.)

Absolutely loved the experiment idea, and how well its steps were written. I also loved that the article included an "observations and results" section. From it, we learned that the materials we used in the activity each played a role in the DNA extraction. For example, "the detergent or soap helps to break down the cell's outer membrane, and the salt helps to separate the DNA from other materials in the cell. And because the DNA doesn't dissolve in alcohol, this substance helps the DNA clump together in a separate layer."  Thank you, author Molly Josephs!

Bravo to Scientific American, and we'll be doing more of their "Bring Science Home" experiments in the future.

RETURN OF AFRONANA:  Imagine my surprise this afternoon when I received an anonymous comment about the Jan. 10, 2013 entry for this blog. The writer came upon MPA in what can only be called, a highly unlikely way ... by researching bananas with afros. Yes, I'm serious.  Here's the comment. ...  

Hello from sunny St. Pete Beach, Florida! On the way to work this morning, in a rather trafficky part of town I saw something bouncing around the lanes and thought "That looks like a banana with an afro!" Even though my Tuesday plan was to put nose immediately to grindstone, I had to do some "research" regarding bananas with afros to see if they were really a thing. And apparently, they are! Have you recently been travelling in or around St. Petersburg, Florida? There are lots of actual Nana's here (with and without afros), and tis the season for visiting grandchildren! Please advise and I will drive through this intersection very slowly on the way home tonight!

Our blog for Jan. 10 included a trip to Goodwill, where we found a fascinating assortment of items, including this. ... 

So apparently 'our' afronana has a twin in Florida. How 'bout that! It was very nice of the St. Pete Beach researcher to drop us a line, dontcha think?

ATOMIC:  A post from a Facebook friend in Belfast turned us on to a great TED-Ed cartoon all about atoms. The five-minute animation does a brilliant job of demonstrating just how small atoms are. I'll bet most people watching this learn something about atoms they didn't know before. 
http://www.youtube.com/watch?v=yQP4UJhNn0I


MATINEE: This afternoon, we finally got around to screening the BBC's animated 90-ish minute version of "The Lion, The Witch and the Wardrobe" from 1979. 

I'm sad to report the kids haven't read any of the Chronicles of Narnia. I was hoping this movie might spur them to do so, but they're in the throes of the Harry Potter books now, so it's probably going to have to wait.

They seemed to enjoy the movie - it held their attention - but the animation wasn't exactly Pixar, shall we say. The movie was showing its age. 

One thing I learned today is that it was directed by Bill Melendez, who is best known for his work on the famous Peanuts animated television specials.