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Table 1 Measurement times required per sample for each of the R dark techniques assessed

From: The combination of gas-phase fluorophore technology and automation to enable high-throughput analysis of plant respiration

Technique Step Description T (min)
Fluorophore Calibration Purge tubes of air using N2 gas or sodium dithionite 0.02–0.05
Sample preparation Dissect tissue (e.g. scalpel, scissors or leaf punch) and place in measuring tube 0.5–1
Measurements In general, slopes taken from 1 to 2.5-h. 186 samples per run. Note: more than 186 samples can be simultaneously measured but cycle time between O2 recordings will increase to >6-min, reducing resolution 0.8
Total   1.3–1.9
O2-electrode Calibration Prepare and assemble electrodes, including application of membrane and electrode solution. Aerate calibration solutions and obtain zero and saturated O2 values after stabilisation of current 4–9
Sample preparation Dissect tissue and place inside cuvette and adjust plunger being careful not to introduce air pockets 1–2
Measurements Slopes taken after stabilisation of signal and before depletion of O2, usually within 10–40 min but dependent on sample 20–40
Total   25–51
IRGA Calibration Change consumables (e.g. soda lime, desiccant, CO2 canister) and zero IRGA chambers 1–2
Sample preparation Select and clip measuring chamber onto leaf 0.5–1
Measurements Allow steady-state gas-exchange to be reached 10–15
Total   11.5–18
MIMS Calibration Apply membrane and test membrane stability. Purge tube and inject known volumes of O2 and CO2. Record background consumption 5–10
Sample preparation Dissect tissue and place inside cuvette and air-seal cuvette 1–3
Measurements Allow signal to stabilise (usually 5 min) and record slope between 5 and 20 min 20
Total   26–33
  1. T (min) represents the estimated time it takes to measure a single sample in minutes. For example, if 20 samples can be measured without recalibration and it takes 20-min to calibrate, then the calibration T is 1-min