
%0 Journal Article
%A Brookes, Justin D. 
%A Geary, Sean M. 
%A Ganf, George G. 
%A Burch, Michael D. 
%T Use of FDA and flow cytometry to assess metabolic activity as an indicator of nutrient status in phytoplankton
%J Marine and Freshwater Research
%D 2000/10/30
%V 51
%N 8
%P 817-823
%K 
%R https://doi.org/10.1071/MF00048
%U https://www.publish.csiro.au/paper/MF00048 
%X This study reports the use of a technique to determine nutrient limitation of cultured and natural phytoplankton. The technique, an FDA-activity assay, which is usually used to assess cell viability, was used to measure metabolic activity in response to nutrient addition; the metabolic activity of phytoplankton was determined as the rate of hydrolysis of fluorescein diacetate (FDA), by intracellular esterases, to fluorescein, which was detectedusing a flow cytometer. Replacement of the limiting nutrient to nitrogen- or phosphorus-limited cultures and field populations resulted in an increase in metabolic activity that was detectable 24 h after nutrient addition. By flow cytometry, the natural phytoplankton community can be divided into different taxonomic groups; the response of these to FDA could be determined individually to allow identification of the nutrients limiting each type of phytoplankton. This would be more specific than the assessment of a whole-community response, which may mask subtle differences among taxa. 
