145
•
<
Figure 2. Aspects of flow cytometric analysis and sorting. Functions
in stippled area (3,4) denote instrument capabilities. Important
developmental needs include: 1) cell collection; 2) cell preparation/concentration/stain protocols; and 5) extended data analysis.
dissociation methods are vi tal to application of flow cytometry/
sorting techniques.
Development needs include single cell separations which preserve the integrity of the cell as a unit.
The current size range of the instrument's capability is between
1 to 150 ).lm which is almost ideal for phytoplankton research.
The
oceans have vast quanti ties of particles wi thin this range.
Still,
by having size limits, we are subject to subsampling a community and
must be aware of the resulting biases.
This working range is
restricted by the fact that a particle of 0.5 ).lm diameter is
approaching the wavelength of light at the small end (e.g. 488 nm).
Yet, some biomedical laboratories are dealing successfully with virus
particles.
To date, a 200 ).lm orifice controls the large end
permitting measurement of particles up to 150 ).lm.
Cell concentrations in the marine environment vary substantially
and are summarized crudely in Table I for oligotrophic, mesotrophic
and eutrophic waters (Yentsch and Yentsch, in press). Note that with
the exception of bacteria, cyanobacteria and other picoplankton, cell
concentrations are far more dilute than the optimal range of 105 to
10 6 cells per ml.
Thus a major developmental thrust must be for
concentrating cells with minimal artifacts.
At the moment in
biomedical labs, cell elutriation looks promising - a process where
counterflow during centrifugation permits concentration with only
minor G forces applied.
Success is being witnessed with oceanic
particles as well (5. Pomponi, pers. comm.) Density gradient centrifugation and plankton Ni tex netting can be effective, but inherent
subsampling biases remain.
While samples can be run at ambient concentrations, one tends to
bias interpretation based on the tremendous logging up of the smaller
•
<
Figure 2. Aspects of flow cytometric analysis and sorting. Functions
in stippled area (3,4) denote instrument capabilities. Important
developmental needs include: 1) cell collection; 2) cell preparation/concentration/stain protocols; and 5) extended data analysis.
dissociation methods are vi tal to application of flow cytometry/
sorting techniques.
Development needs include single cell separations which preserve the integrity of the cell as a unit.
The current size range of the instrument's capability is between
1 to 150 ).lm which is almost ideal for phytoplankton research.
The
oceans have vast quanti ties of particles wi thin this range.
Still,
by having size limits, we are subject to subsampling a community and
must be aware of the resulting biases.
This working range is
restricted by the fact that a particle of 0.5 ).lm diameter is
approaching the wavelength of light at the small end (e.g. 488 nm).
Yet, some biomedical laboratories are dealing successfully with virus
particles.
To date, a 200 ).lm orifice controls the large end
permitting measurement of particles up to 150 ).lm.
Cell concentrations in the marine environment vary substantially
and are summarized crudely in Table I for oligotrophic, mesotrophic
and eutrophic waters (Yentsch and Yentsch, in press). Note that with
the exception of bacteria, cyanobacteria and other picoplankton, cell
concentrations are far more dilute than the optimal range of 105 to
10 6 cells per ml.
Thus a major developmental thrust must be for
concentrating cells with minimal artifacts.
At the moment in
biomedical labs, cell elutriation looks promising - a process where
counterflow during centrifugation permits concentration with only
minor G forces applied.
Success is being witnessed with oceanic
particles as well (5. Pomponi, pers. comm.) Density gradient centrifugation and plankton Ni tex netting can be effective, but inherent
subsampling biases remain.
While samples can be run at ambient concentrations, one tends to
bias interpretation based on the tremendous logging up of the smaller