Re the five-color stuff, one could also try a long-Stokes-shift fluor 
such as Chromeo 494 that is excited together with AF 488 or FITC, but 
that emits in the mid 600s.  No unmixing required but presumes your 
sample can survive sequential scans.

-- 
Robert J. Palmer Jr., Ph.D.
Natl Inst Dental Craniofacial Res - Natl Insts Health
Oral Infection and Immunity Branch
Bldg 30, Room 310
30 Convent Drive
Bethesda MD 20892
ph 301-594-0025
fax 301-402-0396