I need help!

[Baller12]

Hi, I am starting a part of my science project. I am doing, "does dog saliva kill bacteria?". I need to know what to do for "observation"
Please help, thanks!

[deleted-42343]

If your project is due on the 25th, I don't think you will have time to do this experiment.

One way to measure how much bacteria is in a dog's mouth is to take a sample and put it on a special plate with agar (you can read more about that here: https://www.sciencebuddies.org/science- ... p007.shtml). This would take a while since you would need to order the plates and then wait for the bacteria to grow.

I suppose you might be able to look at a sample of dog saliva under a powerful microscope...but I'm not sure how well that would work. It would be much easier to see the results on the agar plates. You might consider comparing dog saliva with human saliva and see if they have more or less than we do.

This project is probably better to save for the next time you do a science project, or if you want to do it for fun! If only a piece of your project is due on the 25th and you will have at least a few weeks to do the entire project, then ignore what I said earlier and you can do it.


If you only have a few days, take a look at this list of project ideas that are short and only require readily available/household materials: https://www.sciencebuddies.org/science- ... arents.php

Since you are in 6-8 grade, look at projects with a difficulty level from 4 to 7.

You can also take our topic selection wizard, which asks you some questions and then suggests projects based on your interests, grade level, and time available: https://www.sciencebuddies.org/science- ... gister.php

You can also browse through all of our project ideas here: https://www.sciencebuddies.org/science- ... deas.shtml

Our Project Guide, which walks you step by step on how to do a science fair project, might also be useful: https://www.sciencebuddies.org/science- ... ndex.shtml

Good luck and let us know if you have any more questions!

[sunmoonstars]

Hi,

That sounds like a really interesting project!

I agree with Amy - you will need a couple weeks to do this one. Spreading the dog saliva on agar plates is the best way to visualize the bacteria that would be present. the colonies will be you "observation" and you can quantitate them by counting the colonies on the individual plates.

I wanted to add that looking at the saliva under a microscope could work, but it isn't quantitatve (meaning you could just say yes or no if the bacteria are there or not). This won't be easy to do since the mmicroscope only lets you look at a very small section of your saliva sample at one time.

[deleted-71536]

Hi there,

I'm not sure if you are still planning to do this experiment. It's a very interesting idea!

I just wanted to add to the excellent advice that Amber gave you. If you want to know whether dog saliva kills bacteria, you could try putting the saliva on an agar plate where bacteria are already growing, and see if the bacteria die. For example, put the dog saliva on only one half of the plate, and compare the bacterial growth on the two sides.

If you want to see if dog saliva has less bacteria than human saliva, then the easiest thing would be to spread human saliva on one agar plate and dog saliva on another. Wait for the bacteria to grow, and count the colonies you see.

Hope this helps!

Heather