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CSIA fee for Service System

 

We have an analytical service for the compound-specific stable isotope analysis (CSIA) of nitrogen of amino acids for measuring the δ15N values (‰ vs, Air) of 8 AAs including Gly, Ala, Val, Leu, Ile, Glu, Phe, and Hyp in biological samples.
 

Price

There are three ways:
(1)  2,496,000 yen (~23,500 US$) for 1-8 samples
(2)  1,996,200 yen (~19,000 US$) for 1-8 samples
(3)  31,200 yen (~300 US$) for 1 injection
 
Both (1) and (2) include HCl hydrolysis, defat, pivaloyl/iso-propyl ester derivatization, and isotope analysis (by triplicate injection) for maximum 8 samples. Difference between (1) and (2) is that we can use sufficient time (120 hours = 5 days) in the former, but only use minimum time (96 hours = 4 days) in the latter. (3) is fee for only one injection of pivaloyl/iso-propyl ester derivatives, which uses 1.5 hours of the analytical serves. We mention that (3) does not include the processing from HCl hydrolysis to the derivatization. Therefore, samples should be extracted and derivatized by yourself (but we never recommend if you need shipment for long distance, more than 6 hours far from Hokkaido University). In the case of (3), please order the total number of the injection for both samples and isotopic reference materials.
 
We would like to generally offer either (1) and (2) in this analytical service: the former includes the time for both analysis of the amino acid δ15N values and education of postdoc/students, while the latter includes the time only for the analysis. You can use (2) if you dislike supporting the education or if your budget is limited, but please mention that our community will have no next generation who can operate CSIA, probably 10 years latter, if the education of postdoc/students was not cared.
 

Authorship

We do not need to find our names in the list of authors in your paper(s), but you should clearly write our names in the acknowledgments to make sure the responsibility of the analysis. Of courses, we are very much happy if you want to include our name in the list of authors after sufficient discussion on the observed data with us.
 

Samples

We need 1.0 mg protein per each sample for the isotope analysis of amino acids. In a general procedure, a sample is freeze-dried and homogenized to fine powder. Then, a portion (0.1-0.3 mg) of the powdered sample is used for the isotope analysis. If sample size is very small (e.g. less than 0.1 mg protein), we should combine several samples to 0.1 mg as one sample for the isotope analysis.
 
We can measure the δ15N values (‰ vs, Air) of, in general, 8 AAs including Gly, Ala, Val, Leu, Ile, Glu, Phe, and Hyp in biological samples, if the amount of these amino acids and chromatographic separation of their peaks are enough to measure the δ15N values.
 
Note: The d15N value of Glu includes a contribution from the a-amino group of glutamine (Gln) because Gln is converted to Glu during HCl hydrolysis. The d15N value of the other amino acids cannot be measured in the procedure above, because coelution issues (for Pro, Asp. Thr, Ser, Met) or no detection (for Arg, Cys, His, Lys, Typ) on the GC chromatogram. We also cannot accept the measurement for some specific samples (e.g. shell, bone, soils, sediments) because these samples require cation-exchange column chromatography and/or other purification.
 

Instrument and Analytical accuracy and precision

  • GC: Agilent 7890B
  • Injector: PTV
  • Column: Agilent Ultra-2 (50m, 0.32mm, 0.52um)
  • Autosampler: Gerster MPS
  • Interface: Thermo GC Combustion III (Oxidation and Reduction furnaces)
  • IRMS: Thermo Delta V
  • Isotopic reference materials: Ala, Gly, Val, Leu, Nle, Asp, Met, Gly, Phe, Hyp (from Indiana University, Shoko Science)
  • Accuracy (mean of cap-delta): 0‰ in general
  • Precision (mean of 1 sigma): 0.4-0.8‰ in general

 

Schedule

In general, we need 3 months for the analysis of 1-8 samples.
 
 
Please e-mail to ychikaraishi_At_lowtem.hokudai.ac.jp, if you consider the use of this analytical service. We recommend discussion with us before ordering, because the analysis is highly dependent on types of samples, particularly the AA and matrix contents in samples.
 
Sincerely yours
 
2020.1.1
Yoshito Chikaraishi, Yuko Takizawa