The microscope is used in a cold room so that video images of living organisms can be recorded. These images are used to help in the identification of organisms and in teaching. The species present are identified at sea by microscopy, but many are too small to be identified with the light microscope. Subsamples are preserved with glutaraldehyde for examination by electron microscopy in Australia. Growth rates of phytoplankton are measured by incorporation of radio-labelled carbon into the cells.
Some experiments involve size-fractionation of the cells.
Bacteria are stained with fluorescent dyes and counted using a light microscope. Cells and other particles in seawater are also counted with a flow cytometer, in which the cells flow sequentially through the beam of an Argon ion laser. On every particle, the scattered light is measured - forward scatter relates to size, side scatter relates to shape. In addition, the green, orange and red fluorescence is measured which allows plant cells with chlorophyll to be distinguished from animal cells, bacteria and detritus. Typically 10000 particles are counted and measured in 2 minutes.