MassAligner - Software
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.