iTutor Biology Updates

I have a failed experiment that I need help figuring out why it went wrong. One of the bacteria (Xenorhabdus Nematophila) did not grow at all, neither played by themselves or cocultured. I am thinking that if I can find a dye to use on the agar plates then I would be able to see if there is any dead bacteria. This way I could find out if there was actually any bacteria played or if there was a mix up of dilution tubes during dilutions.