We like to do activities each weekend at Imagine That. We’ve played with pulleys, vacuums, painted and built marshmallow launchers all in the past month. Each Sunday we also play with slime. This weekend was no different.
We’ve been talking about Grandparent’s Day all week. Our STEAM storytime read stories about staying over with grandparents Llama Llama Gran and Grandpa and How to Babysit a Grandma. We made handprint hearts to share with grandparents after the stories. We also had family tree printouts and pop-up card ideas in the art room all week. Saturday we had two activities you could do with your grandparents.
First, we made some recycled crayons. We warmed up our convection oven to 300 degrees F. Visitors broke up some of our old crayons into silicon molds. We let them melt for 10-20 minutes, then let them cool. We had the option to speed up the cooling in our refrigerator so people could take them home faster.
We also extracted the DNA from strawberries. This is a really fun activity we love to do here. We talked a little about genetics and how we inherit traits from our parents and looked at some of those traits. Then we started squishing up strawberries in sandwich bags. While the visitors were squishing, we made some buffer solution – water, dish soap, and salt. We added some of the buffer solution to each bag and squished some more. We poured our strawberry mix into a cup. Ideally, you would want to filter out the bigger chunks with a sieve or coffee filter. This will help make it easier to see the DNA. If this is too hard, or some of the bigger chunks gets into your cup, don’t worry. You’ll just need some extra rubbing alcohol. It’ll help if the rubbing alcohol is chilled. Strawberry DNA should float to the top as the bubbles start to settle.
Why do we use strawberries? We could use lots of things to find the DNA. I’ve used other fruit, and had some success, but strawberries are great. It’s much easier to break up the strawberry than an apple and easier to deal with the safety issues of fruit instead of raw meat. Strawberries have enzymes like pectinase and cellulase that help to break up cell walls. Strawberries are also octoloid, which means there are 8 copies of each chromosome and a whole lot of DNA to find.
What about the other things in our experiment? Soap and fats don’t get along, so the dish soap helps with the fats in the cells. Salt can help break down the protein chains . Once the cell walls are broken, the DNA can come out. Chilled rubbing alcohol can help the DNA appear as the DNA is not soluble in the alcohol and the DNA is less dense than the rubbing alcohol.
Check out our website for more activities here at the museum. We’ve got more STEAM storytimes, robot and D&D clubs, and more. We’re doing leaf rubbings and leaf chromatography and lots of apple fun coming up this month.