Sample Submission

Submission Instructions

1. Fill out a sample submission form
2. Prepare your samples as described below
3. Keep an eye out for our e-mail with an price estimate and estimated turn-around time
4. Ship or deliver your samples to:
   
   Sample Submission
   Department of Soil and Environmental Sciences
   University of Wisconsin-Madison
   1525 Observatory Drive
   Madison, WI 53706-1299
   
   Or if local, deliver samples to the dropbox in the hallway outside of the UW-Madison Soil Science building, room 170.

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Solid Samples (client prepared)

1. Ensure that sample material is dry and finely ground.
2. Weigh sample material into clean tin capsules (aluminum capsules will not work). For accurate C% and N% make sure to use a balance capable of measuring to 3 decimal places after the mg (e.g. 5.132 mg).
3. For best results weigh out enough material so that the sample contains at least 0.1 mg N and/or 0.5 mg C. This corresponds to ~3-5 mg for dried plant biomass and ~15-30 mg for mineral soils. Accuracy suffers with N or C substantially below these values.
4. There are many acceptable techniques for folding sample capsules. The ideal sample is spherical or cubical with a maximum diameter of 7 mm.
5. After weighing, drop test each sample to make sure it doesn’t leak. Drop each sample 1-2 inches onto a clean surface and inspect to verify that none of the capsule contents leaked out. If there is leakage, discard the sample and start over.
6. Place the weighed samples into a clean 96-well plate and wrap with a rubber band to secure the lid.

Soil Samples (for lab preparation)

1. Ensure that the sample material is ready for grinding and encapsulation. Prior to submission the sample should be thoroughly dried and sieved if necessary. Any fine roots or pieces of biomass included in the sample vials will be ground and analyzed.
2. Place the sample material in a clean microcentrifuge tube. Make sure to include more than is typically needed for analysis to allow for losses during grinding and the possibility of reruns. It is recommended that at least 100 mg of most soils and 25 mg of most plant biomass be included.
3. Seal the microcentrifuge tube by wrapping tightly with parafilm. This will help ensure that the tube does not leak during shipping.

Gas Samples (client prepared)

NOTE: The only vessels we accept for gas samples are 12 mL exetainers.

1. Inspect each exetainer. The condition of the septum is very important, for best results use only exetainers with previously unpunctured septa.
2. Either vacuum evacuate your exetainers or thoroughly flush with zero grade air to remove any traces of CO₂ or CH₄ inside.
3. Using a gas-tight syringe inject 40 µL of gas sample into an evacuated exetainer (or 28µL if using flushed exetainers). Exetainers ship best when slightly pressurized, it also ensures that enough gas is present to allow for preliminary analysis to determine if dilution is necessary.