Waikato Stable Isotope Unit (WSIU)

Breath Samples

The Waikato Stable Isotope Unit is able to offer analysis of delta 13C in breath samples arising from the Urea Breath Test (UBT) diagnosis of Helicobacter (Campylobacter) infection. The following conditions apply:

Sensitivity and Repeatability:

The analysis is done on an 8-10 ml sample of expired breath which is injected into a continuous flow GC/MS (gas chromatography/mass spectrometer). The sensitivity of the technique depends on the repeatability of the analysis. This is illustrated in a sample of four consecutive breath samples from one subject.








Mean -22.78   range 0.43     s = 0.17     CV = 0.75% 

This example illustrates the normal range of values obtained from our instrument. Thus any one value will always be well within 0.5% of the mean and an arbitary level of enrichment of 5% is often taken to indicate infection. All values are normalised to Pee Dee Belemite standard using a secondary standard gas bottle.


Supply samples in duplicate, i.e. two pre- and two post- samples fully labelled and accompanied with a full schedule of samples. The ideal sample container for use is a 10 ml exetainer or vacutainer. Collection is best done by subjects breathing into the tube with a straw, then quickly capping it.


Pricing reflects the set up time, and handling and billing costs for small numbers of samples. It is advantageous for all parties if samples are combined into larger groups for analysis. Prices are for single analyses each of pre-and post- breath samples (i.e. per subject.). The duplicates are to allow for leaked or broken tubes.

Please refer to the Science & Engineering Services Fees Schedule for the latest equipment and analytical costs for external clients.

Analysing a sample

Delivery and Turn-around

We will acknowledge receipt of samples by fax or e-mail. Samples will be run at the next change over of the instrument (ie: when the current sample run is complete, normally 2 - 5 days). If you require urgent analysis, we can oblige, but this will incur a special set-up cost. Results will be faxed or e-mailed as soon as completed.


All care is taken by the University of Waikato, and the Waikato Stable Isotope Unit to provide accurate, standardised results. All analyses are bracketed with known gas standards and related to PDB via a known isotope standard (CSIRO sucrose). While the University undertakes to implement the best possible analytical techniques and procedures, it cannot be held liable for the way in which the results are used by clients or third parties.

Breath samples

Find out how to prepare and submit breath samples for analysis.


For the latest equipment and analytical costs for external clients, please Contact Us.