Expert: Walter Hintz - 1/1/2006

Question
I am using easy gel petri dishes for this experiement.  I read your answer to Mackenzie.  I am a seventh grader doing this for a sciene fair project.  I have two questions.  Some information I read said you need to keep your sample dishes at the same temperature as the source of the sample (i.e. human - 98.6)  Is this not necessary?  The furnace room is ok?  

Second, you said the bacteria would grow in 24 hours.  Will more continue to grow after the 24 hours or does it just need to me monitored for the first 24 hours?

Is there any way to color the colonies to make them stand out for photos?  Can it be done before hand or do they just normally stand out?


Thank you for your help.

Answer
Hi Jake;
 Mouth germs grow best at body temperature but a furnace room would work and most germs grow in 24 hours.  They will continue to grow longer of course.  If you do not get good growth incubate them for another day.. Some bacteria have color but most do not but they will stand out for pictures