Auxin is an important plant hormone for many aspects of plant growth. It is present and active in low concentrations in plant tissue. To allow auxin quantification in small amounts of material such as seedlings, roots and stem tissue, a highly sensitive analytical technique is required.
The most abundant natural auxin is indole-3-acetic acid (IAA). In Dr. Jerry Cohen’s Lab at the Department of Horticulture, University of Minnesota, we have the expertise and sensitive instrumentation needed to accurately quantify endogenous auxin at picogram levels. The protocol measures free IAA in plant tissue by isotope dilution analysis using Gas Chromatography-Mass Spectrometry (GC-MS) and a 13C6 IAA internal standard. The 6 label carbon yields a compound with a mass spectrum distinct from that of endogenous plant IAA.
The IAA extraction protocol works well even with relatively small amounts of tissue (5-10 mg of fresh weight). The protocol involves harvesting of plant tissue, flash freezing, addition of internal standard, amino and polymethylmethacrylate solid phase purification, followed by derivatization with diazomethane. Following derivatization, samples are analyzed on a Thermo Trace GC ultra gas chromatograph coupled with a TSQ Quantum XLS triple quadrupole mass spectrometer.
A complete description of the extraction and analysis procedure is provided here:
Liu, X., Hegeman, A. D., Gardner, G., & Cohen, J. D. (2012). Protocol: high-throughput and quantitative assays of auxin and auxin precursors from minute tissue samples. Plant methods, 8(1), 1-17.
|academic rate||industry rate|
|Each analysis will have a start-up fee:||$250||$500|
|Price per sample (first 20 samples)||$100||$200|
|Price per sample (samples after first 20)||$80||$160|
|Additional data analysis (per hour)||$91.92||$183.84|
If you are interested in submitting samples for analysis or have any questions about the procedure, sample size or preparation, etc. please contact Jayanti Suresh ([email protected]) or Jerry Cohen ([email protected]) for more information. For unusual samples or large submission we will schedule a quick conference call to discuss logistics and/or running feasibility trials prior to sample analysis.
We will always endeavor to provide results as quickly as possible! As the analysis time will depend on demand please enquire as to analysis time at the time of sample delivery.