Question about bacterial growth..help please!

[sbn]

hi I want to do an experiment on bacteria found in make up....but im not quite sure how to or how to test that out..&is there any specific or special equipment i need?please help me!!and give me suggestions and advice

[deleted-71615]

I will provide you with information on how to isolated and count bacteria.

You can refer to the Science Buddies website for information on inoculation here. https://www.sciencebuddies.org/science- ... tion.shtml Identifying bacteria to the species often involve the use of molecular test (PCR) and biochemical testing. You can use gram stain to classify bacteria base on their shape, color and pattern. You will take a colony of the bacteria from the petri dish to perform the gram stain. Here is a website that detail the gram stain procedure http://faculty.stcc.edu/rapp/BIOT251/gr ... cedure.htm Here is a website with pictures of gram stain from different organisms. http://www.uphs.upenn.edu/bugdrug/antib ... l/gram.htm

Counting colony usually does not require one to have any special lab equipment, here is a procedure in quantitative culture method which can be apply to any type of fluid.

Quantitative Cultures
Quantitative cultures should be performed so that the number of bacteria per milliliter can be determined and expressed as CFU/ml. The most common method uses a calibrated platinum loop that delivers 0.001 ml or 0.01 ml of fluid. Each plate is inoculated with one loopful of the fluid, and the colony count is determined by multiplying the number of colonies by the dilution factor. For example, if a 0.001 ml loop is used and 10 colonies are observed, the colony count would be 10 x 10000 or 10,000 CFU/ml (104 CFU/ml). If a 0.01 ml loop is used and 10 colonies are observed, the colony count would be 10 x 100 or 1000 CFU/ml (103 CFU/ml). Use the following procedure to perform a quantitative culture using a calibrated loop
1. Mix the fluid well
2. Vertically insert a flamed and cooled calibrated loop into the fluid and immerse it just below the surface. Only move the loop straight up and down
3. Remove a loopful of fluid and inoculate each plate by making a straight line down the center and then a series of close perpendicular streaks through the first line. Inoculate each plate.

You can review an example here.
http://www.allina.com/ahs/allinalabs.ns ... 052908.pdf

If the bacterial count is low you might not have any grow and will need to use a bigger size loop.
Michael

[sbn]

thank you so much!!(:
umm but do you know how i would test it out?like how would i set up an experiment on how bacterial growth on cosmetic products such as mascara?

[deleted-71827]

Hi!
Here's a general overview on how to do such an experiment:

http://www.hometrainingtools.com/bacter ... de/a/1480/

You can swab the mascara and try to get bacteria from there, and from other types of makeup as well. Hope this helps, and best of luck!

[sbn]

thank you so much!!!(:

[sbn]

do you know what my question can be for such an experiment like this?

[deleted-71536]

You could investigate a question like:

What type of makeup accumulates the most bacteria?

For this, you could get a few different types of used makeup (e.g., mascara, lipstick, face powder) from several different women. (The more people you can ask, the better.) Then you can take small samples from each type of makeup with a sterile cotton swab, and swab the makeup samples on agar plates to see how much bacteria grow.

Does that help?

Heather