The use of stable isotopes (as internal standards) is not a new thing. However using a 95% U-13C internal standard brings a lot to the table. Especially if the internal standard is a complex standard such as metabolite yeast extract which contains 100s of primary metabolism metabolites. Labeled peaks can be easily found using software algorithms and their unlabeled counterparts identified and quantitated. What especially important and unique to this Workflow that by using 95% U-13C internal standards the software can correct for ion suppression and normalize the samples. And the metabolites in these internal standards have been characterized by LC-MS and incorporated into the ClusterFinder software. Workflow and Software all for $200 (for 90 samples).
In short, the Workflow is a high-quality quantitation system that utilizes two (2) complex Internal Standards to make accurate measurements of several hundred metabolites simultaneously in experimental samples and measure day-to-day (QA/QC) platform reproducibility.