thanks for replying
Genecks - I did two controls - one agar plate with olive oil (non-essential oil) and an empty agar plate. I didn't make my own agar because I'm pretty sure I would have contaminated it and its just too messy and annoying. i went with my sister's method.
CharonY - You were right. i didn't get a lawn, just single colonies, so i couldn't even measure the zone of inhibition .. experiment was a fail :'(
i used 'sterile water for injection' from my mom's clinic. is that deionized water? im not sure
plus there were fungal colonies on a couple of the agar plates
the only measurements i made were:
1. number of colonies (very inaccurate and not even related to my method .... i just assumed that the essential oil diffused through the air and inhibited bacterial growth in the whole of the agar plate ).
2. distance to the nearest colony (which is pretty inaccurate too because that just depends on chance , the colonies would grow where the bacteria was swabbed).
i did the well method that my sister told me to do. the filter paper idea seems really cool .. i dont know why i didnt think of that before.
but i dont know what to do now because my project is due in 2 weeks and i have to do all the results, analysis, graphs, discussion, and stuff ... do you think i will have time to do the experiment again? i dont have an incubator. so it will just be bacteria growing at room tempature. but the growth was pretty good at 3 days .
i attached some photos of my results... i did two people. one of them brushed their teeth just before the experiment so i dont' think their bacteria is oral bacteria. they were just recovering from a cold , so maybe its that, . its looks really yuck lol....
1. example of results for subject 1(i have no idea what bacteria this is- maybe cold / flu bacteria?)
best one: they were all pretty bad but i guess the tea tree oil
worst one: all of them
2. example of results for subject 2 (it looks like streptococcus mutans)
best one: peppermint
worst one: control