Dr. Robert Winkler

Position:  Investigador Cinvestav 3B, SNI II

Telephone: +52 (462) 623 9635


Laboratory of biochemical and instrumental analysis




Research » Biotechnology and Biochemistry » Professors/Researchers » Dr. Robert Winkler » Software » Mass Spectrometry Software: ESIprot 1.0


Mass Spectrometry Software: ESIprot 1.0


Electrospray ionization (ESI) mass spectrometry (MS) devices with relatively low resolution are widely used for proteomics and metabolomics. Ion trap devices like the Agilent MSD/XCT ultra or the Bruker HCT ultra are typical representatives. However, even if ESI-MS data of most of the naturally ocurring proteins can be measured, the availability of data evaluation software for such ESI protein spectra with low resolution is quite limited.

ESIprot 1.0 enables the charge state determination and molecular weight calculation for low resolution electrospray ionization (ESI) mass spectrometry (MS) data of proteins.


ESIprot supported evaluation of ESI-MS data of alpha-lactalbumin

Main characteristics of ESIprot 1.0   

  • Algorithm based on standard deviation optimization (scatter minimization)
  • Suitable for peak lists. No raw data and peak intesities required, therefore suitable to re-evaluate “historical” data
  • Highly accurate calculation of molecular weights of proteins, even from low resolution data
  • Only two peaks of one protein required, extremly robust
  • Theoretically unlimited molecular weight range
  • Designed for the analysis of pure proteins
  • Open source license GPLv3: program and parts of it may be used for commercial and non-commerical purposis

Screenshot of ESIprot 1.0



Winkler R.: ESIprot: A universal tool for charge state determination and molecular weight calculation of proteins from electrospray ionization mass spectrometry data. Rapid Commun Mass Spectrom, 24(3),  285-294, 2010,



Windows Installer: ESIprot-1.0.exe

Python Source Code ( and License (GPLv3.txt):