How to avoid Satellite colonies

Although I think satellite colonies don't bother. But I do found some knowledge useful.

Quoted from bioforum:

Ampicillin plates (100ug/mL) often show satellite colonies after incubating for more than 16 hours (my plates show satellites after 20 hours incubation). So it is better to incubate for a shorter period.

Use methicillin/ampicillin. I think it is available from Sigma. Bacteria that can grow in ampicillin can grow in met/amp, but you don't get satellite colonies.

We had the same problem and switched to carbenicillin, while using the same vecotr, and no more satellites but colony growth.

You could also try using carbenicillin instead of ampicillin. Carbenicillin is more stable than ampicillin and so would be effective for a longer period of time. It is, however, very much more expensive.