3. In case the cells are large and sink quickly, you might need to
homogenize the solution before the measurement or have continuous stirring in the cuvette.
4. Dissolve DCMU in ethanol to a final concentration of 2 mM.
The final ethanol concentration in the sample should be <1% to
avoid problems with extraction of photosynthetic pigments.
5. The use of F v as a measure of health/stress should be used with
some caution as different species of algae will have different
ranges of F v depending on, e.g., their photosynthetic pigments
(e.g., cyanobacteria).
6. As a general rule of thumb, F v > 0.5 represents actively growing
cells for eukaryotes, and F v < 0.2 severely stressed cells. Cyanobacteria typically have lower F v than eukaryote algae because of
their different pigmentation not absorbing light well at 440 nm,
which is the typical excitation light, used in fluorometers. This
could be taken into account by adjusting the excitation wavelength or by using DCMU addition as described above [5].
7. Derived from [(F m – blank) – (F 0 – blank)]/(F m – blank).
8. This will be done without blank corrections, which in the case
signal to blank reading is high is not a problem. However, blank
correction might have to be carried out in the case the blank is
high (>10%) compared with F m .
References
1. Falkowski PG, Raven JA (2007) Aquatic photosynthesis. Blackwell Science, Malden, 375 p
2. Suggett DJ, Pra ´s ˇil O, Borowitzka MA (eds)
Chlorophyll a fluorescence in aquatic sciences:
methods and applications. Springer, Dordrecht.
p 323
3. Stribet A, Govindjee (2012) Chlorophyll a fluorescence induction: a personal perspective of the
thermal phase, the J-I-P rise. Photosynth Res
113:15–61
4. Guillard RRL (1975) Culture of phytoplankton
for feeding marine invertebrates. In: Smith WL,
Chanley MH (eds) Culture of marine invertebrate animals. Plenum Press, New York
5. Raateoja M, Sepp€ al€ a J, Ylo ¨stalo P (2004) Fast
repetition rate fluorometry is not applicable to
studies of filamentous cyanobacteria from the
Baltic Sea. Limnol Oceanogr 49:1006–1012
Measurement of Fluorescence for Monitoring Algal Growth and Health
45
homogenize the solution before the measurement or have continuous stirring in the cuvette.
4. Dissolve DCMU in ethanol to a final concentration of 2 mM.
The final ethanol concentration in the sample should be <1% to
avoid problems with extraction of photosynthetic pigments.
5. The use of F v as a measure of health/stress should be used with
some caution as different species of algae will have different
ranges of F v depending on, e.g., their photosynthetic pigments
(e.g., cyanobacteria).
6. As a general rule of thumb, F v > 0.5 represents actively growing
cells for eukaryotes, and F v < 0.2 severely stressed cells. Cyanobacteria typically have lower F v than eukaryote algae because of
their different pigmentation not absorbing light well at 440 nm,
which is the typical excitation light, used in fluorometers. This
could be taken into account by adjusting the excitation wavelength or by using DCMU addition as described above [5].
7. Derived from [(F m – blank) – (F 0 – blank)]/(F m – blank).
8. This will be done without blank corrections, which in the case
signal to blank reading is high is not a problem. However, blank
correction might have to be carried out in the case the blank is
high (>10%) compared with F m .
References
1. Falkowski PG, Raven JA (2007) Aquatic photosynthesis. Blackwell Science, Malden, 375 p
2. Suggett DJ, Pra ´s ˇil O, Borowitzka MA (eds)
Chlorophyll a fluorescence in aquatic sciences:
methods and applications. Springer, Dordrecht.
p 323
3. Stribet A, Govindjee (2012) Chlorophyll a fluorescence induction: a personal perspective of the
thermal phase, the J-I-P rise. Photosynth Res
113:15–61
4. Guillard RRL (1975) Culture of phytoplankton
for feeding marine invertebrates. In: Smith WL,
Chanley MH (eds) Culture of marine invertebrate animals. Plenum Press, New York
5. Raateoja M, Sepp€ al€ a J, Ylo ¨stalo P (2004) Fast
repetition rate fluorometry is not applicable to
studies of filamentous cyanobacteria from the
Baltic Sea. Limnol Oceanogr 49:1006–1012
Measurement of Fluorescence for Monitoring Algal Growth and Health
45