A good place to start is to get in touch with Carleton Stewart at Roswell
Park (Buffalo, NY, USA)...he has done extensive work on detecting residual
disease in leukemias, as well as multi-color (4 and greater) immuno-analysis.
A lit. search will surely bring him up; I'm sure he wouldn't mind a direct
correspondence, either...he's been a mentor in flow cytometry for years.