Science and Our Food Supply: Investigating Food Safety from Farm to Table

1

LAB:

 CONDUCT THE LAB 

1. 

Have the class form a hypothesis about the properly 

refrigerated hamburger versus the hamburger left out at 

room temperature. 

2. 

Now ask: How would you test your hypothesis? Record 

their answers. 

3. 

Discuss a good experimental design for this lab. 

4. 

Ask for three volunteers. 

• 

Remind them to wear safety gloves and lab aprons. 

They should take their sample near the center of the 

meat and away from the surface where the hamburger 

was cut. If possible, get a drop of hamburger juice. 

• 

Have one student label one Petri dish “control.” 

• 

Have the second student label one dish “chilled.”  

Have them swab the properly chilled hamburger, and 

inoculate the “chilled” dish. 

• 

Have the third student label one dish “room  

temperature.” Swab the hamburger that was left  

out of the refrigerator, and inoculate the “room  

temperature” dish. 

5. 

Tell the students that one package of hamburger was 

cut in half to make two packages. Then ask: 

• 

Why did we cut the package in half rather than just 

buying 2 individual packages? (To ensure that the 

meat tested is from the same batch, so as not to 

introduce another variable into the experiment)