Analysing bacteria

Hi,

I'm sorry, this is an ignorant question from a complete beginner, but I am 
using a FacsCalibur flow cytometer to analyse fluorescently labelled 
bacteria. My department hasn't used the flow cytometer for this purpose 
before. The bacteria are around 2 micrometers by 1, labelled with GFP and 
dsRed.

Some of my cultures run through very very slowly and I am not sure whether 
there is something odd about the culture (like cells clumping or 
stickiness - though there is nothing obvious on a microscope) or whether the 
settings need changing, maybe it's only detecting the odd one - but then, 
some cultures seem OK.

At the moment on the threshold window we are using forward scatter as the 
primary thing to detect and it is set to 20, the rest are set to 58 but I am 
told they don't matter. I wondered what settings other people used for 
bacteria or similar sized things.

Many thanks,

Sarah
(postgraduate sudent)