experiment w/ Satellite colonies
 

Hi,

I am looking to conduct an experiment involving satellite colonies. The experiment is based off the pGLO transformation lab that inserts an ampicillin resistance gene, araC, and GFP gene into E. coli. Once grown in LB/amp/ara culture, the transformed E. coli secrete beta lactamase, which breaks down the surrounding ampicillin and allows non-transformed "satellite" bacteria to grow around it.

I'm having some trouble coming up with a suitable experiment to research the satellites. So far my ideas are to investigate the correlation between the ampicillin concentration and number/amount of satellite colonies. So if the ampicillin is increased, the number of satellites should go down. But how would I measure the satellites? Should I count them, measure the radius of the whole colony, or test for the presence of beta lactamase?

If you have any ideas, please help! Thanks!

Re: experiment w/ Satellite colonies
 

You can never have too much data. I would count the number of satellite colonies, measure the various radius and therefore calculate the total AREA of satellite colonies. The only thing about radius is that you would need to be very specific about growth time of various plates. Make sure this is exactly the same or your data might be skewed. A test for B-lactamase would be nice too. This data compounded would give you some nice clean results and a healthy way to back up whatever your conclusion is.

Re: experiment w/ Satellite colonies
 

thanks