The variable-to-maximum fluorescence ratio (Fv/Fm) ratio was measured to evaluate changes in the photosynthesis efficiency of algal cell under different treatments.
The maximum photochemical efficiency of photosystem II of algal samples was detected by measuring variable-to-maximum fluorescence ratio (Fv/Fm) according to the operating procedures on the Dual-PAM-100 (Walz, Effeltrich, Germany).
Bath application of 100 ng/mL TNF α or 100 ng/mL IL-1 β elicited a rise in the relative maximum DCF/CB fluorescence ratio indicative of the formation of ROS.
Individual Ca2+ transients were extracted from each pixel contained within each ROI to calculate minimum (diastolic) and maximum (systolic) fluorescence ratios.
Minimum (Rmin) and maximum (Rmax) fluorescence ratios (340/380 nm) were measured, and cytoplasmic [Ca2+] calculated as with Kd of 1.2 µM.
However, currently available genetically encoded sensors are characterized by low signal intensity and limited dynamic range (maximum change in fluorescence ratio or intensity) [ 1, 4, 5], insufficient for routine applications in high throughput screening (HTS) assays and restricting sensitivity of precise single-cell studies.
Fv/Fm (the variable/maximum fluorescence ratio) indicates the maximum photochemical quantum yield of PSII reaction centers, reflecting the photosynthetic light energy conversion efficiency.
The maximum PSII quantum yield was calculated as the ratio of variable to maximum fluorescence, Fv/Fm = (Fm Fo)/Fm.
The ratio of variable to maximum fluorescence (Fv/ Fm) was used as an indicator of the maximum quantum efficiency of photosystem II.
Electron transport rate (ETR), and the ratio of variable fluorescence to maximum fluorescence (Fv/Fm) for leaf samples were measured using PAM-210 fluorescence meter (Walz, Effeltrich, Germany).
