Laboratory
Here you can find laboratory processes coming after Collection.
Freeze drying
After collection, field samples are stored in a -80 freezer, waiting for freeze drying. The freeze drying process lasts two to three days, depending on the nature and water content of the samples. For example, succulent plants need to be passed twice in the process (4 to 6 days) to be completely dry.
Weighting
When field samples are completely dry, they are weighted. Three scenarios have been tested, following the extraction needs:
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Normal case, the sample weights more than 50 milligrams and there is no need to extract in big quantity: 50 milligrams are weighted and put in a safelock tube of 2 milliliters with three metal beads.
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Exception, the sample weights less than 50 milligrams: The entire field sample is weighted and put in 2 milliliters safelocks. If the weight is under or equal to 10 milligrams, 1 bead is added. If the weight is above 10 and under or equal to 30 milligrams, 2 beads are added. If the weight is above 30, 3 beads are added.
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Bigger extractions: For extractions that exceed 50 milligrams of dry material, there is no special guideline. As the quantity is too big to be extracted in a 2 milliliters safelock, the use of another container is mandatory.
To prepare for extraction, samples are then crushed. Until 50 milligrams of dry material, use of ballmill is the best way. It is why we add metal beads.
Extraction
After weighting, samples need to be extracted. The extraction process we use is the following:
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0.5, 1 or 1.5ml of mix 80% methanol, 20% distillated water ans 0.1% formic acid is added (depending on the original weight).
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Second ballmill to maximize extraction.
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Centrifugated 2 minutes at 13'000RPM
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1.4ml of supernatent is prelevated and stored in 1.5ml vials with non split caps.
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Storage at -80°C.
This extraction protocol is the classical one for the DBGI project. However, our tracking system permits to add other protocols for different purposes (for example bigger extractions than 1.5ml).
Aliquot
The aliquot object is the one that will be injected. It permits to keep the extract in the freezer to limit contaminations and degradations. To proceed, a defined volume of the extract is prelevated and put in another vial containing an insert.
Mass spectrometry
Once aliquots are made, they can be analyzed with a mass spectrometer.
Laboratory Application
All this process is made using a Laboratory Application that permits to collect metadata, to track samples and to print labels.
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