Compound Specific 13C & 15N analysis of Amino Acids by GC-C-IRMS

The Stable Isotope Facility (SIF) will be closing, effective July 26, 2026.

June 3, 2026
An Update on the Plant Sciences Stable Isotope Facility

Dear Faculty, Staff, Students, and Supporters,
After a lengthy review process and careful consideration, we have made the difficult decision to sunset the Stable Isotope Facility (SIF) in its current form, effective July 26, 2026.

The Department of Plant Sciences continues to face hard decisions surrounding funding allocation given the campus-wide request to reduce budgets. Over the past several years SIF has been operating with a significant and growing deficit and, despite extensive efforts over the last several months to find a solution that would allow the facility to continue to provide services to the research community, we have not found a model that is financially sustainable.

I want to thank SIF’s staff for their excellent work and dedication these past 25 years, and everyone who has played a role in supporting this facility.

We are committed to doing our best to support the researchers who rely on the facility during this transition, and will be in touch with individual clients about details of specific plans for handling existing orders over the next several weeks.

Sincerely,
Daniel Potter
Professor and Chair, Department of Plant Sciences
University of California, Davis

Original Letter

Compound Specific 13C & 15N analysis of Amino Acids by GC-C-IRMS Tips
 

Sample requirements
In general, we request samples weights of 6-9 mg for protein-rich animal tissues and 25-35 mg for plant materials (including algae). Smaller samples sizes may be suitable, if necessary, but please contact us.  Sample materials must be clean, dried, and homogenized prior to sample submission to the SIF. 

Shipping
All projects are accepted on a case-by-case basis and must be scheduled with the SIF prior to sample submission. Samples arriving at the SIF without prior approval will be returned at the shipper's expense.

Samples should be shipped dry in 0.5-1 dram glass vials (see Supplies). If samples are known to be particularly lipid-rich, lipid extraction is recommended prior to submission. 

First, complete and submit the online Analysis Order Form and Sample List for your samples. Shipment may proceed once you receive email confirmation from SIF staff.  Be sure to also include a printed copy with your samples. The SIF uses both electronic and hardcopies to track your samples and to contact you regarding receipt of samples, data, and invoicing. For mixed analysis requests, we require the completion of a separate Analysis Order Form and sample list for each type of analysis.

Supplies


Manufacturer / Part#

Description

 Unit

Spectrum Chemicals / 840-29809-CS

1/2 dram (2mL) Qorpak Clear Glass Threaded Vials with PTFE Lined Cap

144/PK