393
to oceanography in meaningful ways. For flow cytometry to play its optimum part in this
process, its technical limitations (such as detection of small signals, specificity in the face of
a heterogeneous community, and efficient sampling of "rare" particles) must be recognized
and addressed.
Even as capabilities for flow cytometric analyses expand, we should recognize that the best
way to realize our goals in oceanography entails the combination of complementary
approaches, both for single cells and for bulk properties. For example, image analysis (which
provides detailed analyses of relatively small numbers of cells) has already been combined
with a flow system to study zooplankton (Kachel et at. 1990), and the combination confers
obvious advantages over either technique alone. An example of the power of coupled bulk and
individual cell analyses has already been described, in revealing the "identity" of the
prochlorophyte picoplankton using flow cytometry, HPLC and electron microscopy. This story
is continuing with analysis of the phylogeny of cultured isolates of this group through
molecular biological techniques; strain-specific fluorescent probes from these studies, perhaps
coupled with flow cytometric detection, could then allow study of variability among natural
populations of related clones of these organisms in the ocean. Individual cell analyses may
even play an important role in enhancing our interpretation of satellite images, the ultimate
in bulk measurements, for studying the global ocean.
ACKNOWLEDGEMENTS
We thank Ginger Armbrust, Brian Binder, Raffaella Casotti, Michele DuRand, Donald Frankel, Sheila Frankel,
Ralf Goericke, Heidi Sosik, Daniel Vaulot, and John Waterbury for valuable discussions and advice. This work
was supported in part by NSF grants OCE 88-14332 and OCE 90-12147 (to R.J.O.), OCE 83-16616, OCE
84-21041, OCE 85-08032, OCE 86-14488 (to S.W.C.), by ONR contracts NOOOJ4-83-K-066J, 84-C-0278,
87-K-0007 (to R.LO. and S.W.C.), and by an NSF Graduate Fellowship (to l.A.D.).
REFERENCES
Ackleson SG, Balch WM, Holligan PM (1988) White waters of the Gulf of Maine.
Oceanography 1(2): 18-22
Ackleson SG, Robins DB (1990) Flow cytometric determinations of North Sea phytoplankton
optical properties. Netherlands Journal of Sea Resarch 25: 11-18
to oceanography in meaningful ways. For flow cytometry to play its optimum part in this
process, its technical limitations (such as detection of small signals, specificity in the face of
a heterogeneous community, and efficient sampling of "rare" particles) must be recognized
and addressed.
Even as capabilities for flow cytometric analyses expand, we should recognize that the best
way to realize our goals in oceanography entails the combination of complementary
approaches, both for single cells and for bulk properties. For example, image analysis (which
provides detailed analyses of relatively small numbers of cells) has already been combined
with a flow system to study zooplankton (Kachel et at. 1990), and the combination confers
obvious advantages over either technique alone. An example of the power of coupled bulk and
individual cell analyses has already been described, in revealing the "identity" of the
prochlorophyte picoplankton using flow cytometry, HPLC and electron microscopy. This story
is continuing with analysis of the phylogeny of cultured isolates of this group through
molecular biological techniques; strain-specific fluorescent probes from these studies, perhaps
coupled with flow cytometric detection, could then allow study of variability among natural
populations of related clones of these organisms in the ocean. Individual cell analyses may
even play an important role in enhancing our interpretation of satellite images, the ultimate
in bulk measurements, for studying the global ocean.
ACKNOWLEDGEMENTS
We thank Ginger Armbrust, Brian Binder, Raffaella Casotti, Michele DuRand, Donald Frankel, Sheila Frankel,
Ralf Goericke, Heidi Sosik, Daniel Vaulot, and John Waterbury for valuable discussions and advice. This work
was supported in part by NSF grants OCE 88-14332 and OCE 90-12147 (to R.J.O.), OCE 83-16616, OCE
84-21041, OCE 85-08032, OCE 86-14488 (to S.W.C.), by ONR contracts NOOOJ4-83-K-066J, 84-C-0278,
87-K-0007 (to R.LO. and S.W.C.), and by an NSF Graduate Fellowship (to l.A.D.).
REFERENCES
Ackleson SG, Balch WM, Holligan PM (1988) White waters of the Gulf of Maine.
Oceanography 1(2): 18-22
Ackleson SG, Robins DB (1990) Flow cytometric determinations of North Sea phytoplankton
optical properties. Netherlands Journal of Sea Resarch 25: 11-18