Icky Sticky Fingers #3 UPDATE

Icky Sticky Fingers #3: I ran into a couple of problems with this version, however I think I can adjust a few things to make it work. The issues I ran into are summarized below:
While the nutrient agar firmed up beautifully in the refrigerator, it melted when I put it out in the garage. I think the agar could use a little more gelatin so that it remains firm at warmer temperatures.

• Since bacteria grow well at body temperature (~98 degrees), I thought putting it in the garage would be the best place in the house (~100 degrees). It was way too warm in there and the gelatin melted. I decided to put it in the laundry room (much cooler, but the warmest place in our house...about 80 degrees). Most of the petri dishes firmed back up nicely.

Results: So far, I am noticing some really nice bacterial growth on all of the dishes, except for the control (yay!). If you look carefully at the top two photos, you'll notice the the dirty hands petri dishes have the most bacterial growth (you can't see the paper towel pattern through the media). While both clean hand petri dishes have bacterial growth, it is much less than the dirty hand petri dishes. The control petri dish was not touched at all and has no growth at all. WooHoo! Success! And such a cheap and easy experiment!

Icky Sticky Fingers Part 3!

Why not start another version of this experiment??? This time, I'm going to run the Icky Sticky Fingers experiment using petri dishes and homemade nutrient agar. I was excited to run across this very simple, very cheap recipe for nutrient agar on the internet as it could prove useful in my life science classes this year. All you need is some unflavored gelatin, a little bit of sugar, and some beef broth. You can find the recipe for nutrient agar HERE. They turned out beautifully, we'll see how they hold up over time.

Disposable petri dishes: $5.00/20 (these can be reused, sterilized in a solution of bleach water).

Gelatin: $2.50 for 4 packets.

Broth: I used prepared broth as opposed to bouillon cubes. The cost was about $1.00 per can. Each can of broth will make about 12 petri dishes.

Icky Sticky Fingers #1 and #2 UPDATES!

It's update time!

Icky Sticky Fingers Part 1: It's been 15 days and there is still no mold growth. This bread has some serious shelf life! I'm really glad we decided to try out a different type of bread with slightly different incubation temperatures due to the location (it's a lot warmer here than it was in Tahoe). I wonder how long it will take for this bread to show a little mold growth? Only time will tell...

Icky Sticky Fingers Part 2: It's only been 3 days and I'm seeing some significant mold growth! I'm getting some mixed results using the preservative free whole wheat bread. Paige's results are turning out great with the dirty bread showing more mold growth than the clean bread (see picture #1, upper left hand, top row). Charlie's dirty slice of bread has less mold growth than his clean slice of bread (see pictures #2, center (front of bread) and upper right hand (back of bread), top row). The control has the most mold growth (maybe I touched it too much when taking it out of the bag???). I'll give it a few more days and see what the final results end up being.

Icky Sticky Fingers Update

One of the most frustrating things about science is experiments that don't turn out as expected. It's been 11 days since my mom and I began our Icky Sticky Fingers experiment and I still do not see any type of mold growing on the bread (grrrr!). For a lot of students (and teachers, for that matter), this can be quite an obstacle to overcome ("My experiment failed, what do I do now?" "What do I tell my classmates/students?" "How do I explain the outcomes?" "Should I even spend more time on this?"). 

I have had many experiments turn out differently than I expected in my own classroom. What I have learned over time is that this situation is made a little easier when students come up with an explanation on their own. I have them brainstorm in small groups reasons for the outcomes that were observed. Together as a class, we decide which direction we want to go (this is modeled really good in the TV series, Mythbusters). This works well in the secondary classroom, but can be modified for the elementary classrooms with a little more teacher direction. It's hard though, with time constraints we are constantly dealing with, pacing guides, limited to no classroom budgets, and exhaustion, it is easy to say, "Forget it, let's just move on to the next unit."But you know what? We learn just as much from an experiment turns out differently than we predicted than from the ones that turn out exactly as we thought they would. 

My mom and I brainstormed some of the possible reasons why this didn't work in the time we expected it to. Some of the reasons include:

• The temperatures in Tahoe were fairly cool at night and pleasant during the day resulting in slower mold growth.
• The bread contained more preservatives that we expected (which would account for a longer shelf life).

While we will continue original experiment until we see mold growth on the bread (I'm curious how long it will actually take), today we started another experiment using a preservative free whole wheat bread from Trader Joes. From experience, this bread spoils pretty quickly (which is why I keep it in the refrigerator), so perhaps we'll get better results. Other than the type of bread and the location, the experiment was run exactly the same way as the first one. 

Additional updates coming soon!

Icky Sticky Fingers Part 1

Every year my husband, two kids, and I go camping in Lake Tahoe with my parents during the summer. We soak up the rays, bury our feet in the sand, eat way too many smores, and enjoy our time together.

This year, my mom and I spent some time putting together a healthy habits mini-unit for her first grade classroom (which will be up on my Teacher Pay Teacher shop soon). This mini-unit focuses on the importance of washing your hands in order to minimize the spreading of germs. This experiment will provide her students with a visual model that there are small organisms, commonly known as "germs", (bacteria, fungi, viruses) living on their hands and that certain organisms can make you sick if ingested. Most of the organisms that will grow on the bread will be fungal since bacteria and viruses have specific living requirements. Who knows, maybe she'll have fewer absences throughout the year!

Since we were going to be camping together for almost two weeks, we decided to try it out with my own kids, because when are kids more germy and dirty than when they're camping?

The setup:
We gathered five pieces of whole wheat bread because there aren't as many preservatives as there are in white bread (less preservatives means more mold growth in a shorter amount of time). In addition to bread, we got 5 zipped baggies and a spray bottle of water. Voila! We're ready to run an experiment with two very eager and dirty little munchkins.

The experimental process:

First we rounded up two very dirty little kids.

Ewww!

Next we rubbed their grubby little fingers over both sides of freshly purchased slices of whole wheat bread. 

Then my 3 year old son lightly sprayed one side of each of the bread slices since moisture helps promote mold growth.

Now that the first part of the experiment was done, it was time to herd the kiddos into my parents' trailer for a thorough washing of their hands. To make sure that their fingers were really clean, we followed the traditional soap and water regimen with a little hand sanitizer. 

With their clean hands, probably the cleanest they've been since we started camping, we began part two of the experiment.

Look at those cute, clean little paws!

We had the kids rub their clean hands all over both sides of a new slice of whole wheat bread, then we placed the slices of bread in new, labeled zipped baggies. Each baggie got a small spritz of water, just as we did with the dirty slices of bread.

All five samples were placed in a brown paper bag and left to sit in a warm dark place until any mold growth is noticed. 

How long will it take? We have no idea. Don't you just love science?!? We're going to wait until we notice any mold growth and then at that point set certain amount of time, like 5 days or so. It is important that all of the bread have the same amount of time to grow mold so that we can accurately observe and compare the amount of mold growing. Ultimately, we're going to compare the mold growth on the dirty and clean slices of bread to a control; the slice of bread that hasn't been handled. This comparison will help us see how much and how fast the mold grows on bread with varying amount of contamination/handling on it in a certain amount of time.

Now all there is left to do is wait....

Expected Outcome:

If all goes as expected, the dirty slice of bread should grow the most mold in the same amount of time as the clean slice of bread and the control slice of bread because the kids transferred additional "germs" (bacteria, fungi, etc.) to the bread when they touched it with dirty hands. The clean slice of bread and the control slice of bread will grow mold as well, however it should be less because fewer "germs" were transferred to the bread. Only time will tell...

Updates will be coming soon!

Presenting for California Science Project

It was such an honor to be invited to present at California Science Project's Northern Inland Summer Institute, Earth in Balance. I presented my interactive notebooks; the what, the why, the how, as well as student examples. You can check out my PowerPoint at the California Science Project Northern Inland website (HERE). In addition to a PowerPoint presentation, I handed out a bunch of materials that I use in my interactive notebook, of which I will post pictures of on this blog soon.

In addition to presenting, I also got to participate in many wonderful activities. We had many great presentations by various Chico State professors, including Dr. Nichols, Dr. Teasdale, Dr. Maslin, Dr, Kagan, and Dr. Mayor. Each had great activities that can easily by brought back to the classroom, but the presentation that had me itching to get school started up again was the one by Dr. Kagan, a Chico State physics professor. His demonstrations on the physics of balance were great. We found the center of mass on a baseball bat, irregular shapes made of paper, as well as many other objects. He also does a great job of explaining the physics behind baseball with many activities that can be used in the classroom. Check out his website, Major League Physics (HERE), for access to these free resources. I'm already compiling a list of things I want to have my 8th graders do next year!