MassAligner - Software

Published: 10 December 2020| Version 1 | DOI: 10.17632/dd3p5tfcd7.1
Breno San-Martin


Acquired data were aligned according to the m/z ratio using an in-house software, called. Briefly, the results from a DIMS analysis consists in a table of 2 columns: m/z and intensity, been each row the information of one m/z ion and its respective intensity. Different samples contain different ions, generating distinct m/z columns between samples. For statistical analysis, as PCA and PLS-DA, it is necessary that one column remains constant in all samples, as for example for LC-MS data, time is the column used as constant. On DIMS analysis, there is no separation, so time cannot be used as constant. Therefore, it is necessary to align the m/z columns from all samples. The MassAligner software algorithm creates a column containing all the acquired m/z in all samples, but removing redundancies. After that step, it searches in the original table from each sample the intensity of each m/z in the column. When a m/z is not present in that particular sample, the software input zero as intensity. Thereof, the final result is a worksheet within all the samples, with the same m/z column, i.e. a constant column. MassAlign allows round the decimal cases in m/z column, since high resolution m/z data requires higher computational power. It is important to highlight that similar results may be achieved with R or Python algorithms; however, the use of such platforms requires previous knowledge in computing programing. For this reason, we developed MassAligner software to be user friendly, regarding previous programing knowledge.



Universidade de Sao Paulo Instituto de Quimica de Sao Carlos, Universidade de Sao Paulo, Universidade Federal de Sao Paulo Escola Paulista de Medicina