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Getting started

Select a matrix and choose your preferences to get customized metabolite ranges

Getting the reference ranges of a customized subpopulation depending on your preferences is really easy

  • In the My biocrates portal, click on Browse the Quantitative metabolomics database (QMDB) to enter the database
  • Select the matrix you are interested in and set your preferences regarding donor attributes like age, BMI etc. in the filter options
  • If you or your organization are a contributor to the database contents, you will be able to choose if you want to see data based on all samples or samples from your own organization only
  • If you are interested in a specific class of metabolites, or in certain metabolites only, you can restrict the classes and/or metabolites displayed in the display options
  • The Calculate reference ranges button starts the calculation based on your settings
  • Once the results are displayed, they can be exported with the export button menu
  • You can save the current filter selection and restore saved filter selections in the Settings menu
  • Please also check out the section Features of the QMDB and our video tutorial

Excel template for visualizations and statistics​

The provided Excel template facilitates data visualization and significance testing

Data visualization​

  • The QMDB export contains the median, mean, minimum, maximum, 1st quartile, 3rd quartile, and interquartal range values for each metabolite. A statistical software can be used to generate boxplots from these values directly
  • Alternatively, boxplots can be created using MS Excel. The Excel template by biocrates can facilitate this. Just paste the table exported from the QMDB into the first tab and find your boxplots in the fifth tab
  • If you prefer a direct comparison of QMDB export to your own data or compare several QMDB exports, just paste the second dataset into the second tab and find the boxplots in a side-by-side comparison in the sixth tab

Statistical comparisons​

  • Even though individual sample concentrations are not provided in the QMDB exports, you can still compare the exported ranges to your own data or other QMDB exports using the mean, the standard deviation and the number of samples in a “comparison of means“ test
  • The “comparison of means“ test requires normal distribution of the data, so make sure to use log values instead of the original concentrations. The QMDB export menu contains the option to generate the export from log2 transformed concentration values
  • In the Excel template, paste the table from the log2 transformed QMDB export in the corresponding columns in the third tab. Paste the log-2 transformed corresponding second dataset in the fourth tab. Find the fold changes and p values in the seventh tab
  • Note that even very small differences will be statistically significant when the sample number is very high. The threshold to reach significance may have to be set higher than in conventional statistics