I havent work with flow cytometer, but i came across this article, may be it is useful. Rogers, C. E., Navas, C., Bush, K. F., Dyble Bressie. A novel, transportable flow cytometer facilitates algal quantification in cultures and environmental samples. BD Biosciences, October 2011. Technical Bulletin
Hi Lee. We studied selectivity of feeding of rotifers on mixtures of microalgae. So we got citograms with a series of distinct clusters corresponding to different algal species. It was amazing. I have a page with some examples but it is in Russian - http://ibssequipment.at.ua/index/issledovanie_selektivnosti_pitanija_kolovratok_s_pomoshhju_protochnoj_citometrii/0-21 Anyway, look at pictures)))
First, use a monoculture with middle cell size. Set chlorophyll channel (FL4 on FC 500) as discriminant, start measurement to optimize voltage and amplification settings for FL4 and FS (for algal mixtures it is better to use LOG scale). You finally get a distict cluster in the center of cytogram. After this, prepare polyspecies mixture and test it. Ideally, you get well-isolated clusters but it depends on the species (differences in their cell size and chl content). For our experiments we had to use the species which produce spaced clusters.
as Vladimir Mukhanov explained..but if you use FASCalibur there are many available protocols that can help you a lot.. anyway its useful to read them:
Marie D., Brussaard C., Partensky F. and Vaulot D. Flow cytometric analysis of phytoplankton, bacteria and viruses. 1999. In: Current Protocols in Cytometry. John Wiley & Sons, Inc. 11.11.1-11.11.15.
How to count picoalgae and bacteria with the FACScalibur flow cytometer