Science Buddies: "Ask an Expert"

I'm about to start a period at school where we are supposed to choose our own project to deal with over a period of 3 months. I'm going to do the thawing and cooking of meat project, but I wonder if there are some ways to extend the project so that it can last about three months?
What are the best ways to count bacteria? (petrifil, agar-plates etc.)

Hi GreenValley,

This experiment is very interesting! The Science Buddies project suggests several options for extending the experiment. Firstly, it suggests to estimate the magnitude of error in the bacterial counts, since serial dilutions often produce error. To do this, you could perform at least 3 different serial dilutions and take the average of the 3 bacterial counts. Since there are multiple parts to the experiment (i.e. thawing in the refrigerator vs at room temp, cooking the meat in microwave vs oven) performing several replicates and doing standard deviation calculations and other statistical analysis will surely lengthen your experiment. Also you could repeat your experiment, but with different varieties of meat and introduce a new question, such as which meat is more prone to bacteria or do different types of meat differ in which thawing/ cooking technique minimize bacteria. Other extensions to your experiment could include exploring what are the most common types of bacteria present in meat or what is the optimal thawing/cooking time to produce the least bacteria. In the project, steps 3 and 4 of “Measuring the Number of Bacteria Present in a Meat Sample” in the procedure describe how incubation and a stereo microscope could be used to count bacteria. If you want any more additional ideas on how to count bacteria, you may find this website useful: http://classes.midlandstech.edu/carterp ... %20ss5.htm.

Good luck with your experiment!

Catherine M

Thank you so much for a good answer, CatherineM99!