P700 & Chlorophyll Fluorescence Measuring System

Immediately after its market launch, the DUAL-PAM-100 became the gold standard for parallel recording of photosystem II and photosystem I activities. The DUAL-PAM-100 excels by its outstanding opto-electronical properties which are based on the use of latest-generation components and precision engineering.

The basic system consists of a high performance PAM chlorophyll fluorometer to analyze photosystem II, and a dual wavelength absorbance spectrometer to analyze photosystem I. A ground-breaking pulse-modulation technique has been developed to measure these two signals concurrently and at outstandingly high time resolution.

In principle, the system measures a single-channel signal together with a two-channel difference signal. In the basic system, these two signals are PAM fluorescence of photosystem II, and the absorption change of photosystem I. The DUAL-PAM-100 is not confined to the analyses of photosystems I and II. For instance, the accessory “P515/535 emitter-detector module” measures scattering changes as single-channel absorption signal at 535 nm, and the electrochromic band shift of membrane energization as two-channel signal with 515 nm as sample and 550 nm as reference wavelength.

• Red, blue, and far-red actinic light. Saturating single and multiple turnover flashes.
• All light sources can be switched with 2.5 μs time resolution under software control.
• Saturation pulse method for photosystem I analysis.
• Klughammer-Flux method to determine the number of electrons flowing through a PSI reaction center per time.
• Fully programmable using script files. Macro recorder for easy programming of triggered run tables.

Front view of Power-and-Control-Unit DUAL-C of the DUAL-PAM-100 and of the DUAL-PAM FIBER-Version, DUAL-PAM/F.

The DUAL-PAM measuring system is available as MODULAR Version (DUAL-PAM-100) and as FIBER Version (DUAL-PAM/F). The MODULAR Version has light sources and signal detection located in separate measuring heads, the sample is placed between measuring heads, and photosystem I absorption changes are measured in the transmission mode. The FIBER Version has light sources and signal detection in the central unit, the sample is placed in front of the fiber optics, and photosystem I absorption changes are measured in the remission mode.

The measuring heads of the MODULAR version can be easily exchanged. Using various accessory modules, the MODULAR VERSION can measure the electronic band shift caused by membrane energization, NADPH fluorescence, fluorescence of pH-sensitive dyes, and fluorescence at two different wavebands. The FIBER version lacks this flexibility but may be advantageous when only photosystem II and photosystem I activities are of interest.