Soap Wins

Hey—just an interesting note tonight. Sean did his science fair project on hand sanitizers. Soap won. Since we have no way of telling which organisms we grew on our agar plates, we just did a timed test to see which one killed the bacteria the fastest (We could have stained them gram pos/neg…. but we did not do that and Lord knows it would be too difficult to count them!)

Soap killed the bacteria in 3 minutes, the apple hand sanitizer from bath and body works killed the bacteria in 5, hospital grade epi-clenz killed it in 7 minutes and the alcohol gel (Germ-X) was still working on it at 9 minutes out.

Of course we know that the hospital grade stuff kills more strains of bacteria…. Like MRSA and also kills yeast and VRE….. We just tested the germs found on our hands in our own house.

We used Method Lavender soap from Target, in case anyone was wondering.

Sean’s hypothesis was that the hospital grade stuff would be the best, but soap won instead! Good lesson learned, huh!?





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Look what is Growing

Preparing for the final steps of Sean's experiment. You can see the dots, those are bacteria colonies. Fun stuff. To make agar plates, simply buy agar flakes at Whole Foods or another store. Mix according to the package directions and add to the petri dishes. For Matthew's sterile plates, we boiled the petri dishes and made sure all utensils were sterile, etc. This way we knew if water grew from the water samples, there really was bacteria in the water!

Growing Cultures on Agar Plates

Here's what is growing on the agar plates:

Getting Ready for the Science Fair

last week we prepared everything. Sterile agar plates to test water quality for Matthew. You can see him adding water samples to the plates (petri dishes) and Sean made agar plates to grow bacteria so that he can later test which hand sanitizer kills the most germs.