moored buoy

The CytoSense flow cytometer may be used as as an effective realtime monitoring tool on a fixed in-situ mooring provided there is electrical power and data transmission capability. Data transmission is a challenge since the data generation of flow cytometry is several orders of magnitude higher as compared to common physical entities. Scanning particle data such as the CytoSense format and video-imaging applications increase that data load with another one or two orders of magnitude respectively. The throughput of power and data through a cable is increasingly difficult or costly (marine grade fiberoptic) with the length of the cable, limiting full bandwith applications in practice to shore or very near shore deployments.

An example of such an application is the study of the behaviour of micro-organisms (phytoplankton and microzooplankton) in a shallow stratified lake. A CytoSense instrument was mounted on a floating platform in such a small lake, connected with a cable to shore. A series of depth profiles was taken automatically with the sample intake hose lowered mechanically and dovetailed with the flow cytometric sampling. This allowed the detection of the vertical migration behaviour of multiple individual species on a very fine scale (centimeters - hours).

For larger distances to shore the power can be supplied by a pack of batteries, possibly fed by some solar panels, whereas the data communication can be wireless. Satellite transfer of megabytes is extremely expensive which in practice limits the application of this technology to neare shore applications by means of radio or cell phone communication. The radios suited for cytometry data transfer have to make a line of sight contact which means a maximal distance out of shore of ca. 10 km.

A CytoBuoy is a complete solution with a CytoSense flow cytometer in a small buoy with solar panels and wireless control of the instrument.

  Photo: COPPE/UFRJ (Rio de Janeiro, Brasil)