Microfluorimeter for Studying the State of Photosynthetic Apparatus of Individual Cells of Microalgae

A fundamentally new microfluorimeter is designed to assess the functional state of primary photosynthesis in individual phytoplanktonic cells. The device is tested during a sea expedition. It allows estimation of the amount of photosynthetic pigments, the primary photosynthetic efficiency, the light slope of the linear electron-transfer rate (light response curve) as well as the degree of nonphotochemical quenching of excited pigment molecules in every cell found in a studied phytoplankton community. This data enables plotting of the distribution diagrams of algal cells for each of the listed characteristics within the population of every algal species. The microfluorimeter has a convenient graphic interface where a user can save the measurement results to spreadsheets. The detection limit of the device is equal to 1 pg of chlorophyll inside the photometric volume. This sensitivity is high enough for the reliable quantification of chlorophyll-fluorescence parameters of individual algal cells. The microfluorimeter is equipped with a system that maintains the object temperature constant over a wide temperature range limited from below by the dew point and water condensation on the cover-glass surface.