What can I use to count the amount of bacteria?

Question

I have a problem in how I can go about determining the before and after concentrations or amounts of bacteria. The goal is to determine whether a certain brand of mouthwash or certain method of rinsing is better. I will swab the inside of my mouth and transfer the sample onto a petri dish and gel to allow growth. After some time of growth, I will subject the bacteria growth to the mouthwash. How can I go about determining or measuring how much bacteria I had before and after adminstering the mouthwash? I don't necessarily need a count, but a % reduction would work as well. Any suggestions on a method I could use, some type of equipment, or even any modification I could use in my approach to accomplish the task of comparing before and after?

Answer 1

to test the effects of mouthwash on bacterial growth in vitro i first recommend you use liquid cultures. you should swab your mouth and inoculate a liquid culture. after some time you can split the culture into 2 tubes with equal volume. treat the bacteria in one tube with the mouthwash and treat the other tube with water (untreated control). then use a spectrophotometer to follow the growth of bacteria in each tube, comparing the growth of the treated against the untreated. the problem with an in vitro approach is that the results may not accurately describe how different mouthwashes compare when actually used at full concentration inside the mouth. a more rigorous test would require a lot of people, each swabbing their mouth before and after treatment with a mouthwash and then determining which one killed the most bacteria, expressed as a percent reduction.

Answer 2

On your streak plate either do the quadrant method or the radiant method these methods will decrease the amount of colonies to only a few rather than hundreds, you can do mathematics of population growth or direct microscopic vount of bacteria. Good luck!

Answer 3

You try this via know-how how enormous the viewing area of your microscope is whilst in comparison with the size of your specimen. If at 1000X magnification you're seeing one million/10 of a millimeter^2 of your specimen, and the specimen is a hundred mm^2 entire, then once you concentration on a given area you're staring at one million/one thousand of the full floor area. So, for this occasion, in case you have been to count form 50 person bacterium you will possibly multiply that via one thousand and you will possibly get the full bacterial count form. (it extremely is for incredibly even distribution of micro organism) in case your micro organism is separated into small colonies, you utilize a similar consumer-friendly concept. initiate via understanding how extensive your viewing area is, degree the width of an common colony, then count form the form of micro organism you will discover. Multiply via the exterior area ratio you have usual and you have the form of microorganisms in a colony. Multiply that my the form of seen colonies and you have an estimate of entire inhabitants. while you're counting distinctive forms of micro organism, do a similar component for one and all interior your pattern.