FlowCAM Ballast Water Example:

In order to ensure that treated ballast water is meeting the Ballast Water Performance Standard [D2 Regulations] set by the IMO’s international convention, it is a requirement that viable cells within certain size ranges be detected and enumerated. The FlowCAM® is ideally suited to monitor treated ballast water and is being used by research groups as a tool to determine the efficacy of different ballast water treatment method.

The organisms used during this study, with the FDA protocol and stain, were two dinoflagellates and one chlorophyte. Two results are presented:

                                                                  

Live Test	Dead Test
Figure A	Figure B

 

Live Test: When looking at live cells, (Fig. A), they acquire FDA stain (highlighted in blue) with a mean green fluorescence (Ch2) value of 3268.48.

 

Dead Test: For the dead test, (Fig. B) there is almost a complete absence of Ch2 (green fluorescence) observed when the cells are preserved, as the cells do not acquire the FDA stain (mean Ch2 fluorescence = 220.84). The FlowCAM® scatter diagram in Fig B. (Ch2) clearly shows that all the cells are dead. For both tests, the mean Ch1 fluorescence remains nearly constant (between 2967-3115), indicating the presence of chlorophyll (red fluorescence) within all the cells.

 

Conclusion: When the cells are viable, the FDA stained population (shown in blue) is clearly distinguishable from the non-viable cells within the same sample (shown in red in Fig. A).