[thedoc (OP)]

Clare O asked the Naked Scientists:
   Is there any chemical/dye used to identify common surface born germs for use under a microscope ?If there is what chemical/dye is it?
What do you think?

[evan_au]

Biologists have developed a variety of chemical stains that make bacteria more visible under a microscope.
Many bacteria are quite transparent in their natural state.

Note that some of these chemicals are quite toxic, as they were selected for their ability to attack living cells and attach dye molecules.
Avoid swabbing down your kitchen bench with these chemicals!

[Bored chemist]

It's also worth noting that they are not specific. they stain just about everything.
For example, if you did spray them on your kitchen worktop, they wouldn't just stain the bacteria so you wouldn't be able to tell where the bugs were.

Some of them are not very toxic- so if you are wondering about using them in a school science lab or something they are not unreasonable.
This stuff
https://en.wikipedia.org/wiki/Methylene_blue
is one of the less nasty ones.