Can someone recommend automated workstation for serial dilutions in 96-well plate?

from your description, what you need should be micro-plate fluorescence or absorbance reader.

for the fluorescence micro plate reader, I would strongly suggest the PTI reader, which seems to me should be the best
http://www.pti-nj.com/PlateReader/

for absorbance, would recommend SpectraMax
http://www.moleculardevices.com/pages/instruments/readers_main.html?gclid=CP_d_tTWlo8CFQluIgodI3CVHg

Thank you for quick answer. Sorry, I was not precise. I use SpectraMax for absorbance reader. I need automated workstation that can make serial dilutions with multi-channel micropipette in 96-well micro-plate. That is a step in the assay where my hands get tired of resuspending and transferring from wells to wells :).