I suspect you may be screwing up the coverslipping step.  This will cause a
significant degradation of the image.  you might check to see if your
slides look okay under DIC (Nomarski) using a conventional LM.  Be sure you
are not using too much mounting medium, are using the correct thickness
coverslip (probably 1.5), and that it is clean.  good luck.
 
>Hi,
>        I am a novice in the realm of confocal microscopy. I apologize if
>some of my questions sound trivial. I am working with mammalian cells and my
>first attempt was awesome: staining my cells with a fluorescent phallotoxin
>for actin and propidium iodide for DNA (surely well known already to all of
>you). I got beautiful well resolved images.
>        However, I am now trying other things with disappointing results.
>Viability assays as well as staining with labeled antibodies are giving
>blurred images, both in fixed and non-fixed preparations. The optical system
>is checked, since I saved some of the preps mentioned above and continue to
>give good resolution. Is this common? I don't think so, and I have run out
>of variables to control and change.
>Probably you would like more details about how I worked with this in order
>to give suggestions, but anyhow, any ideas are welcome.
>        Thanks!
>
>                                                           Susi