CMOS based image cytometry for detection of phytoplankton in ballast water

TL;DR

This paper presents an image cytometer (I-CYT) capable of detecting and quantifying phytoplankton in various water environments with high accuracy, useful for ballast water treatment monitoring.

Contribution

The study introduces a novel CMOS-based image cytometer for phytoplankton analysis, demonstrating its effectiveness outside laboratory settings and in assessing ballast water treatment systems.

Findings

Limit of detection of 10 cells/ml

Quantification accuracy between 0.5 and 0.7 log

High correlation with standard flow cytometry

Abstract

We introduce an image cytometer (I-CYT) for the analysis of phytoplankton in fresh and marine water environments. A linear quantification of cell numbers was observed covering several orders of magnitude using cultures of Tetraselmis and Nannochloropsis measured by autofluorescence in a laboratory environment. We assessed the functionality of the system outside the laboratory by phytoplankton quantification of samples taken from a marine water environment (Dutch Wadden Sea, The Netherlands) and a fresh water environment (Lake Ijssel, The Netherlands). The I-CYT was also employed to study the effects of two ballast water treatment systems (BWTS), based on chlorine electrolysis and UV sterilization, with the analysis including the vitality of the phytoplankton. For comparative study and benchmarking of the I-CYT, a standard flow cytometer was used. Our results prove a limit of detection (LOD) of 10 cells/ml with an accuracy between 0.7 and 0.5 log, and a correlation of 88.29% in quantification and 96.21% in vitality, with respect to the flow cytometry results.