colonies - (Feb/28/2006 )

I plated some bacterial cells containing Amp resistant plasmids, incubated them at 37oC overnight. The colonies were small. I sealed them the next day and left the plates in the fridge for 2 weeks and discovered big white colonies near the clolonies that I initially saw before putting the plates into the fridge.

Does anyone have any ideas why?

Thank you.

u r plating the amp resistant plasmd containing culture yes then after some time what will happen is around that a satellite colonies will grow those are very small in size and around the colony a zone is having no amp that is why some colony may be bacteria or fungi also grow

I agree with balu...sounds most like satellites, although those are less likely with refrigeration?

they're not fuzzy, are they?

had the same problem except that next to my big colonies there were strange small colonies....however i went on with the experiments and they never effected the results...

Thanks, balu, aimikins and kathy.

The colonies are big and round.