are bacteria visible if they are cultured in a petri dish??
2007-01-28 11:50:42 · 9 answers · asked by Anonymous in Science & Mathematics ➔ Biology
im just trying to prove that anti bacterial soaps wont kill all fo the bacteria. so i only need see if they do or do not exist
2007-01-28 12:16:46 · update #1
im just trying to prove that anti bacterial soaps wont kill all fo the bacteria. so i only need see if they do or do not exist
2007-01-28 12:16:49 · update #2
If you mean an individual bacterium, then yes you need a microscope in order to see that. Bacteria sizes range from .5 to 5 micrometers, which is impossible for the naked eye to see. However, bacteria in a petri dish will most likely form colonies, which are basically groups of a whole bunch of bacterium smooshed together in a circular shape that you can see with the naked eye. If your culture is new, you can count the number of colonies to get and idea of how many individual bacterium there are in your sample. If you let the bacteria grow, however, the colonies will eventually collide into one another until you get a bacterial lawn, where enough colonies combine to cover the whole plate. Sometimes the bacteria dies before that happens though.
The type of growth agent you use will also affect whether you see bacteria. Some mediums are general use, like nutrient agar, so you can grow a number of bacteria with them. Others are more species specific, such as tomato juice mediums.
2007-01-28 12:04:05 · answer #1 · answered by nobletsunami87 1 · 0⤊ 0⤋
Bacteria In A Petri Dish
2016-11-15 08:38:25 · answer #2 · answered by sushil 4 · 0⤊ 0⤋
Yes, you would want to use a petri dish for this experiment. But this really isn't something you could just do without the assistance of a lab.
First off, it's not just a petri dish, but one filled with agar. Agar is the jello-like stuff that the bacteria would grow on. You would want to apply the antibacterial agents, then touch the agar gently to try to transfer any bacteria from your hands to the agar. You would then have to put it in an incubator for 24-48 hours. This incubator would keep it at body temperature, which would allow the bacteria to grow. They would continue to grow and divide until the few bacteria you put on the plate would be so numerous you could see them.
FYI- you're totally right that these products don't kill all the bacteria, but you might have a challenge culturing things off of you hands like this. A better experiment might be to have one person wash their hands properly without any antibacterial products, another use the alcohol based antibacterials. Then try this 15 minutes later, and show that they both have about the same amount of bacteria on them.
If you don't have access to a lab, I'm sure you can find someone on the internet who has done the same thing.
2007-01-28 12:41:34 · answer #3 · answered by lizettadf 4 · 0⤊ 0⤋
Hi Bert C!!!
Yes, you do need a microscope to look at bacteria. You can see the colonies growth, but the actual bacteria, is to small to be seen with the naked eye.
Even though is bacteria, some are very interesting to look at, others are plain nasty looking!!! Even scary!!!
You can actually buy a microscope and create your own petri dishes, to grow bacteria, so you can take a look at them.
When I was at the University, I did a study and I did not only observed, different types, but i also draw them. I found the most beautiful colorful amoeba!!!! My professor at that time took it, and preserved it in acrylic. Real neat!!!
GOOD LUCK, GOD BLESS YOU and HAPPY LIFE
A.Z.
2007-01-28 12:13:47 · answer #4 · answered by Alliv Z 4 · 0⤊ 0⤋
The bacteria themselves are microscopic, however different agar plates (petri dishes) or other medium used to grow bacteria change color with bacteria growth. A good growth can be indicated by this color change. You can see evidence of a colony of good growth, but you will not be able to see individual bacteria.
2007-01-28 11:53:53 · answer #5 · answered by Raine 4 · 1⤊ 0⤋
you cant see single bacteria by naked eye in a dish,but if you culture them and you can see the whole culture...the antibacterial soap can kill some of the bacteria not all of it......it can't kill the eggs though...
2007-01-28 13:41:03 · answer #6 · answered by phopper megga blaster 2 · 0⤊ 0⤋
If I were to put urine in a culture dish, yes, the next day I can see the bacteria. You can smell it too. If it's green, and shinny, it's E coli. and on, and on. It's really interesting to see. I love it. ~~~
2007-01-28 11:56:08 · answer #7 · answered by Anonymous · 0⤊ 0⤋
Once it colonizes you can see it, but if you want to take a close up look you need a microscope.
2007-01-28 11:55:06 · answer #8 · answered by shendley04 3 · 1⤊ 0⤋
yes, if there are enough of them to form a colony
2007-01-28 11:54:04 · answer #9 · answered by Gruntled Employee 6 · 1⤊ 0⤋