Hi there

I've been using IsoCorrectoR for deuterium calculation in all my datasets - thanks for this great package!

I just had a question about how the Mean Isotopic enrichment calculation is done. We have been using the MeanEnrichment.csv as our final output as an indicator for looking at the percentage of deuterium incorporation in our data. Please confirm if the mean enrichment files gives us the ratio of newly synthesized to pre-existing metabolite pool. we are assuming this ratio is a ratio between Natural isotopic abundance corrected (M1 + M2 +...Mn) and M0. Mn refers to the last detected isotopic peak provided in the measurement file. Please let us know if this is true.

Hi,

basically, the mean enrichment is the amount of labeled tracer element atoms in the molecule in relation to the total number of tracer element atoms that can basically be labeled. In your specific case, of all H atoms that could be labeled, what is the fraction of deuterium isotopes (after correction)?

Mean enrichment (me) is calculated as follows: me = (1 * n1 + ... + i * ni + ... + k * nk)/(k * (n0 + ... + ni + ... + nk)), where k is the maximum number of tracer element atoms in the molecule that can be labeled, and ni is the corrected abundance of the molecule species with i tracer isotopes incorporated. If all tracer element atoms are labeled, we only have the nk species and all others are 0. This corresponds to 100% mean enrichment: (k * nk)/(k * nk) = 1.

Kind regards,

Paul