Summary of the properties of the counting methods.

aAt the time of counting. Note that in our standard procedure, the sample is homogenized in 500 μl and then diluted (if needed) to the optimal concentration for counting. This dilution step is not required except for samples to be counted with the Coulter Counter, for which a dilution of ~20-fold into Isoton or some comparable solution is needed. Thus, for counting with the Coulter Counter, the algal concentrations in the original homogenate must be correspondingly higher. Summary of the properties of the counting methods.