How do I use this? What did I do wrong?
Okay, so I'm doing a science fair project on whether antibacterial soap is effective and it's not working. I used 4 different chopsticks, put human saliva on them, and washed 3 of them with either different types of soaps or a different amount of time. i let the tips of the chopsticks touch the Petri dishes with blood agar and I replaced the lids and put then away...it should have started to grow bacteria by 48 hours...it is past 48 hours and it's close to 72 hours...what did I do wrong...could someone help me.