Applications for MINI-PAM-II: O₂ + Fluorescence Configuration

Simultaneous Recording of Fluorescence and Oxygen

Fluorescence measurements were carried out with a MINI-PAM/B fluorometer to which an FSO2-1 system (optode plus oxygen meter) was connected via an FSO2-AK interface. The sample in a KS-2500 cuvette was stirred by a MKS-2500 stirrer. Both, the fluorometer’s fiberoptics and the optode were connected to the suspension cuvette.

The light regime consisted of 5 min illumination periods alternating with 5 min of darkness: the PAR increased from the first to the last illumination interval (Fig. 1). Saturation pulse analysis was performed at the end of dark and light periods.

The slopes of light-driven oxygen increases were similar for all light intensities (Fig. 1 and 2). In comparison, the photosystem II yield Y(II) at the end of light periods decreased with light intensity (Fig. 1). The discrepancy can possibly be explained by the fact that Y(II) is related to the QA redox state, whereas the oxygen signal is related to the turnover of QA.