Z985 Cuvette AquaPen

Z985 AquaPen is a cuvette version of the Z980 AquaPen chlorophyll fluorometer. It has blue and red measuring lights that enable chlorophyll fluorescence measurements of photosynthetic parameters both in algal and cyanobacterial suspensions in a cuvette. Due to its ultra-high sensitivity – up to 0.5 μg Chl/L, the Cuvette AquaPen can make measurements in natural water samples containing low concentrations of phytoplankton.

The Z985 AquaPen includes the chlorophyll fluorescence kinetics protocols for measurements of OJIP, NPQ and Light Curve responses of QY.  In addition optical density (OD) at 680nm and 720nm can also be measured.  The unit has both data transfer option via Bluetooth and USB communication technology.  With a built-in GPS module and a rechargable Li-ion battery it is ideal for use in the field. The AquaPen comes with PC software for data transfer and visualization.  A Probe version of the AquaPen (Z980) allows the same measurements of chlorophyll fluorescence in suspension by directly placing the probe in the suspension medium.

  • Hand-held chlorophyll fluorometer for algal suspensions placed in a cuvette
  • High chlorophyll detection sensitivity – up to 0.5 ug chl/L
  • Includes 4ml cuvettes
  • Measurements of Optical Density at 680 and 720nm
  • Software and data transfer to PC module via USB and Bluetooth included
  • GPS module included
  • Rechargeable Li-ion battery

NPQ and Light Curve Protocols

  • Three predefined NPQ protocols differing in the duration of light exposure and dark recovery phase as well as in the number of intervals between the pulses
  • Typically used for quantification of photochemical and non-photochemical quenching in dark-adapted samples
  • NPQ 1 protocol: light duration 60s, 5 pulses; dark recovery duration 88s, 3 pulses
  • NPQ 2 protocol: light duration 200s, 10 pulses; dark recovery duration 390s, 7 pulses
  • NPQ3 protocol:light duration 200s, 10 pulses; dark recovery duration 60s, 2 pulses
  • Three predefined protocols differing in number and duration of light phases and light intensities
  • Based on pulse modulated fluorometry (PAM)
  • The effective quantum yields of photosynthesis are determined under various light intensities of continuous illumination.
  • Light response curve relating the rate of photosynthesis to photon flux density
  • LC1 protocol: 6 phases with 60s duration (10, 20, 50, 100, 300, 500 uE)
  • LC2 protocol: 5 phases with 30s duration (100, 200, 300, 500, 1000uE)
  • LC3 protocol: 7 phases with 60s duration (10, 20, 50, 100, 300, 500, 1000uE)

Software – sample data

Sample NPQ data

Sample OJIP data

OJIP parameters
  • Bckg = background
  • F0: = F50µs; fluorescence intensity at 50 µs
  • FJ: = fluorescence intensity at j-step (at 2 ms)
  • Fi: = fluorescence intensity at i-step (at 60 ms)
  • FM: = maximal fluorescence intensity
  • FV: = FM – F0 (maximal variable fluorescence)
  • VJ = (FJ – F0) / (FM – F0)
  • Vi = (Fi – F0) / (FM – F0)
  • FM / F0
  • FV / F0
  • FV/ FM
  • M0 or (dV / dt)0 = TR0 / RC – ET0 / RC = 4 (F300 – F0) / (FM – F0)
  • Area = area between fluorescence curve and FM (background subtracted)
  • Fix Area = total area above the OJIP fluorescence transient – between F40µ and F1s(background subtracted)
  • SM = area / FM – F0 (multiple turn-over)
  • Ss = the smallest Sm turn-over (single turn-over)
  • N = SM . M0 . (1 / VJ) turn-over number QA
  • Phi_P0 = 1 – (F0 / FM (or FV / FM)
  • Psi_0 = 1 – VJ
  • Phi_E0 = (1 – F0 / FM)) . Psi_0
  • Phi_D0 = 1 – Phi_P0 – (F0 / FM)
  • Phi_Pav = Phi_P0 – (SM / tFM); tFM) = Time to reach FM (in ms)
  • ABS / RC = M0 . (1 / VJ) . (1 / Phi_P0)
  • TR0 / RC = M0 . (1 / VJ)
  • ET0 / RC = M0 . (1 / VJ) . Phi_0)
  • DI0 / RC = (ABS / RC) – (TR0 / RC)

Formulas Derived From:
R.J. Strasser, A. Srivastava and M. Tsimilli-Michael (2000): The fluorescence transient as a tool to characterize and screen photosynthetic samples. In: Probing Photosynthesis: Mechanism, Regulation and Adaptation (M. Yunus, U. Pathre and P. Mohanty, eds.), Taylor and Francis, UK, Chapter 25, pp 445-483.