MultispeQ Protocols

A collection of protocols for the MultispeQ

Photosynthetically Active Radiation (PAR)

Use the MultispeQ’s PAR sensor to measure light intensity (400-700nm) in µmol photons × s⁻¹ × m⁻², which represents the Photosynthetically Active Radiation.

This protocol outputs the PAR value, as well as the raw values for the red, green, and blue channel of the sensor.

Photosystem II efficiency (ϕₗₗ)

Basic protocol to measure the Photosystem II efficiency called phi2 or \(\Phi_{II}\). From the fluorescence trace several more values are produced, including \(F_{S}\), the steady state fluorescence, \(F_{M}\), the maximum fluorescence, and LEF, the linear electron flow, based on phi2 and the ambient light intensity.

Photosynthesis (RIDES)

Measures the same photosynthesis-related parameters in <15 seconds as ‘Leaf Photosynthesis MutlispeQ v2.0’ plus additional PS1 and P700 measurements.

  • Chlorophll Fluorescence: Phi2, PhiNPQ, PhiNO, NPQt, qL, LEF

  • Relative Chlorophyll

  • ATP synthase conductivity, proton motive force parameters through DIRK(ECS): ECSt mAU, vH+, gH+

  • Saturation pulse estimation of PSI parameters: PS1 active centers, PS1 open, PS1 oxidized and PS1 over reduced

  • Absorbance at: 450, 535, 605, 650, 730, 850, 880, and 940nm.

  • The rate of turnover of the cytochrome b6f complex through DIRKP(700)

  • Leaf Thickness (in mm), angle, and cardinal direction

  • Leaf Temperature and differential from ambient temperature

  • Environmental conditions: PAR and ambient temperature/pressure/humidity

Important

Supports MultispeQ V1 and V2 with Firmware 2.34 and higher

Relative Chlorophyll Content (SPAD)

This protocol measures basic absorbance at 650 nm and 940 nm and calculates the relative chlorophyll content.

The value returned represents the Special Products Analysis Division (SPAD) to make it comparable to other instruments used in the field.

\(SPAD = k \times \log_{10}\frac{Abs_{940nm} / ref. Abs_{940}}{Abs_{650nm} / ref. Abs_{650}}\)

\(k\) is a proprietary correlation coefficient used in the Minolta’s calculation of SPAD.

Note

Only works with MultispeQ v2.0