MathBench >

Microbiology

 

Frank's Story (read this before you read the other modules -- only 2 pages)

Meet Frank, a college sophomore with a Swedish roommate. One evening after a rough game of flag football, he came down with a sore neck, and by morning he had a pounding headache, an aversion to light, and a rapidly spreading rash. And this is just the beginning of what happened to poor Frank...

Frank's Football Fiasco

Meningitis is a disease is caused by very rapidly multiplying bacteria. How can we measure the growth rate of this bacteria, and why does a log-transformed graph help us a lot more than a regular one? And once we know the growth rate ... how long does poor Frank have?

Frank Gets Messy: In search of Exact Doubling Time

In Frank's Football Fiasco (above), we explored the growth rate of meningococcal bacteria using some very easy numbers. But life is not so easy, and Frank wants to know _exactly_ how long before he can breathe a sigh of relief. Write new improved (but only slightly more complicated-looking) equations for growth and predict down to the millisecond.

Methods for Counting Cocci

Our early explorations suggested that Frank should have been dead in a matter of hours. Luckily for him, Frank's body is not quite as cushy as a petri dish. We need to measure his infection, but how? Compare different methods of measuring bacterial populations and pick the best one for the task at hand.

Viable Plate Count... or, how to count to a milion

We're gonna get serious about counting in this module, with a bit of estimating and multiplying thrown in just to keep things interesting. Practice all the steps involved in doing viable plate count by serial dilution. So many ways to practice it will knock your socks off!

 

Experimenting with Meningicocci ... DRAFT VERSION

Eye of a newt, toe of a frog ... just a few ingredients that you will probably NOT use when you create a culture medium to investigate the effects of rich media on how fast those meningococci multiply. You be the scientist ... pick your own sampling times, count the plates, drag the data onto the graph, and finally ... ta-da ... calculate the doubling time in each media. And what does this mean for Poor Frank?!