The integrity and accuracy of the data are essential conditions for obtaining statistically and biologically meaningful analysis results subsequently. Based on ensuring the rationality of the experimental design and the accuracy of the experimental data, BiotechPack first checks the integrity of the data, removes or supplements missing values, deletes outliers, and performs normalization between samples and metabolites to ensure parallel comparability between samples and metabolites. In the raw data, metabolites with more than 50% missing values will be removed and will not participate in subsequent analysis; the expression levels of metabolites are log-transformed and normalized using the Autoscaling method (Mean-centered and divided by the standard deviation of each variable). The following diagram shows the distribution of positive ion mode data before and after normalization, indicating that the data is approximately normally distributed after normalization.
