I'm hoping someone with more experience can help us identify these: [PLAIN]http://img600.imageshack.us/img600/4836/1ugmlamp2crop2.jpg [Broken] This image was acquired at 40X phase contrast. This summer, we have been trying to amplify a plasmid (provided by Monique) in E. coli. We have colonies on plates, the control plate is clear (LB agar + 50 ug/ml ampicillin), but our starter cultures have been.... disagreeable. The image above is from a starter culture obtained by innoculating LB broth + 10 ug/ml ampicillin with a single colony from the LB/ampicillin plate. The rods are (most likely) E. coli, but we don't know what those bulbous bugs are. Unfortunately, there are bacteria that are naturally resistant to ampicillin- Pseudomonas and Klebsiella, both of which will appear similar to E coli- so we haven't ruled out contamination. If anyone can identify what we have, I'd appreciate it.