Science U
Backwash Science Experiment
Season 2 Episode 1 | 1m 46sVideo has Closed Captions
Have you ever caught someone drinking out of the milk carton? Does saliva wash back?
Have you ever caught someone drinking straight out of the milk carton? Does saliva wash back into the milk carton from your mouth when you take a drink? ScienceU campers tested for the amount of bacteria in milk samples when they drank directly from the carton ("backwash") and when they used a glass (the "control").
Problems playing video? | Closed Captioning Feedback
Problems playing video? | Closed Captioning Feedback
Science U is a local public television program presented by WPSU
Science U
Backwash Science Experiment
Season 2 Episode 1 | 1m 46sVideo has Closed Captions
Have you ever caught someone drinking straight out of the milk carton? Does saliva wash back into the milk carton from your mouth when you take a drink? ScienceU campers tested for the amount of bacteria in milk samples when they drank directly from the carton ("backwash") and when they used a glass (the "control").
Problems playing video? | Closed Captioning Feedback
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What?
What's the matter?
You drank out of the milk carton and then put it back!
When you drink from the carton, you put spit in the milk!
Really?
We can prove backwash happens by putting powdered drink mix in our mouths to color the saliva!
The color swirling around in there proves a little of your spit goes back in your drink!
That's my backwash!
And what's so wrong with that?
Germs!
Bacteria!
Let's test it!
To test for backwash bacteria, half the campers drank milk straight from the carton- and half the campers - the "control group" - used a cup.
And everybody left milk in the bottom of the carton to test for bacteria.
The campers then put the samples in an incubator for four days to grow whatever got into the milk.
So here's the bacteria when we used a glass.
I don't see any bacteria!
That's what's in your backwash - look at all that bacteria!
Most of the bacteria in your saliva are either helpful or harmless!
But if you're sick and you drink straight from the carton... You can spread those germs to somebody else!
Kids: So use a glass!
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Science U is a local public television program presented by WPSU