150
or monitoring position (channel) and C/V both before and after
experimentation.
A. Experimentation with clonal cultures:
Many cultures are ideal candidates for flow cytometric analysis.
Dinoflagellates, however, grow to cell densities which are more
dilute than optimum.
Cu1 tures. of the New England red tide toxic
dinoflagellate GonyauZax tamarensis var. exaavata (clone GT-429) were
grown in F/2 medium at 15 0 C under various photon flux densities in
continuous light for 11 days. 100% represents _ 266 ~Ein.cm-2.s-1.
Flow cytometric analysis of 2000 cells (following centrifugation at
2000 G for 5 m to concentrate cells) indicated an increase in
chlorophyll fluorescence emission (>630 nm; log scale LIRFL) and
parallel decrease in cell size as measured by forward angle light
scatter (FALS, linear scale) (see Fig. 3). Numbers of cells analyzed
is sufficient to permit rigorous statistical analysis.
It can be
quickly demonstrated that there are dramatic 1) increases in cell
chlorophyll fluorescence emission; 2) decreases in cell size; and 3)
decreases in coefficient of variation (C/V) of cells at reduced
photon flux densities. Corresponding division rates for cells were
0.36 day-1 at 100%; 0.45 day-1 at 50%; and 0.20 day-1 at 25%.
g: GT 429
§
100% Light
J
50"0 Light
" ~
{;
.;:. ~
'" <:>
~
25% light
' "
oS
\;
~
.;:.
z
z
Figure 3. Three-dimensional bivariate 64 channel x 64 channel plots
of fluorescence on a three decade log scale (LIRFL) ;:; ch1 a and
forward angle light scatter (FALS) ;:; ch1 size plotted against
relative number of events.
2000 cells were analyzed in each case
using 50 mW 488 nm laser line on a Coulter EPICS V flow cytometer/
sorter.
B. Grazing experimentation:
We want to use many different phytoplankton cells simultaneously
and monitor the rate of decrease of each upon exposure to a
grazer(s).
For the data here, we have selected 514 nm excitation
using an argon-ion laser because it "favors" the phycoerythrincontaining cyanobacteria.
or monitoring position (channel) and C/V both before and after
experimentation.
A. Experimentation with clonal cultures:
Many cultures are ideal candidates for flow cytometric analysis.
Dinoflagellates, however, grow to cell densities which are more
dilute than optimum.
Cu1 tures. of the New England red tide toxic
dinoflagellate GonyauZax tamarensis var. exaavata (clone GT-429) were
grown in F/2 medium at 15 0 C under various photon flux densities in
continuous light for 11 days. 100% represents _ 266 ~Ein.cm-2.s-1.
Flow cytometric analysis of 2000 cells (following centrifugation at
2000 G for 5 m to concentrate cells) indicated an increase in
chlorophyll fluorescence emission (>630 nm; log scale LIRFL) and
parallel decrease in cell size as measured by forward angle light
scatter (FALS, linear scale) (see Fig. 3). Numbers of cells analyzed
is sufficient to permit rigorous statistical analysis.
It can be
quickly demonstrated that there are dramatic 1) increases in cell
chlorophyll fluorescence emission; 2) decreases in cell size; and 3)
decreases in coefficient of variation (C/V) of cells at reduced
photon flux densities. Corresponding division rates for cells were
0.36 day-1 at 100%; 0.45 day-1 at 50%; and 0.20 day-1 at 25%.
g: GT 429
§
100% Light
J
50"0 Light
" ~
{;
.;:. ~
'" <:>
~
25% light
' "
oS
\;
~
.;:.
z
z
Figure 3. Three-dimensional bivariate 64 channel x 64 channel plots
of fluorescence on a three decade log scale (LIRFL) ;:; ch1 a and
forward angle light scatter (FALS) ;:; ch1 size plotted against
relative number of events.
2000 cells were analyzed in each case
using 50 mW 488 nm laser line on a Coulter EPICS V flow cytometer/
sorter.
B. Grazing experimentation:
We want to use many different phytoplankton cells simultaneously
and monitor the rate of decrease of each upon exposure to a
grazer(s).
For the data here, we have selected 514 nm excitation
using an argon-ion laser because it "favors" the phycoerythrincontaining cyanobacteria.