Isotopic Distribution Calculation

Li et al’s Memory-efficient calculation of the isotopic mass states of a molecule


The isotopic distribution calculator comes as a compressed file packaged with everything (we think) you will need to calculate mass states/spectra. Once unzipped, double-clicking on “isotopecalculator.exe” will start the application.

QUDeX-MS Isotopic distribution
Isotopic Distribution

What is the best Isotopic Distribution output format of calculations performed in the calculator?

The program itself does not visualize calculations, and the output needs to be graphed in an additional program (i.e. Excel, Matlab, R, etc.). Suggested ways of doing this are now described in the manual.

Further questions about the usage of the calculator, as well as reports of missing library files in the package, should be directed to Joey Salisbury (

To cite this software in a publication, please use the following reference:

QUDeX-MS: hydrogen/deuterium exchange calculation for mass spectra with resolved isotopic fine structure

Based on our publication Liu et al. (2014), we present QUDeX-MS, an interface for analyzing hydrogen/deuterium exchange MS data with resolved isotopic fine structure.

Li L, Karabacak NM, Cobb JS, Wang Q, Hong P, Agar JN., Memory-efficient calculation of the isotopicmass states of a molecule, Rapid Commun Mass Spectrom, 24(18):2689-96 (2010).


Reference: QUDeX-MS: hydrogen/deuterium exchange calculation for mass spectra with resolved isotopic fine structure. Salisbury JP, Liu Q, Agar JN, BMC Bioinformatics 2014; 15(1):403.

Quick Installation Note: After downloading and launching installer, the installer will initiate download and installation of the MATLAB Runtime Component, which is several hundred megs. The stand-alone version, once installed, may take up to a minute or more to open once run, during which the MATLAB Runtime Component is initiated. There is no splash page currently to let you know it is opening, so please be patient.

Download MATLAB version (includes source code, for academic use only):

Local Download (App Installer) | QUDeX-MS @ MATLAB Central File Exchange | QUDeX-MS @ SourceForge

QUDeX Sample Data | QUDeX for MATLAB (Scripts Only)