Waters | Nonlinear Dynamics

Progenesis QI

The next generation in LC-MS data analysis software.
Discover the significantly changing compounds in your samples.

Support for Progenesis MetaScope

Support for this compound search method is provided as standard.

About this plug-in

This identification method is intended to support identifications from a number of different compound databases. It allows you to choose a .SDF, .CSV, .XLS or .XLSX file containing identifications and information on a selection of compounds, and search for matches by neutral mass.

It also allows you to search retention time and CCS values using additional properties files, and fragmentation data using either theoretical fragmentation patterns or fragment databases.

The MetaScope search method, with an example file and parameters chosen.

The MetaScope search method, with example parameters chosen.

The use of this method has the following steps:

  1. In the Identify Compounds screen, filter the list of compounds to show only those that you want to identify.
  2. Choose a set of search parameters from the Choose search parameters drop-down (you might need to first create or edit a search parameter set. See the section on search parameters below for how to do this).
  3. Click the Search for identifications button.

When the import and search is complete, a prompt will tell you how many compounds have been identified. You can then continue with your analysis, identifying further compounds if necessary by searching with other parameter sets.

Search parameters

MetaScope comes with a number of built-in search parameter sets, to show you the kind of parameters you can set. However, you'll probably want to create your own or modify the built in parameter sets.

To edit or create a new search parameter set, choose the appropriate option in the drop-down to the right of the parameter set name:

MetaScope edit or create new search parameter set drop-down

This will pop up a dialog where you can fill in the various search parameters:

The MetaScope search parameters dialog

Briefly, the options available to you are:

Give the search parameter set a useful name to refer to later.
Compound database
Choose either an SDF or CSV/XLS/XLSX file containing compound information.
Mass within
Choose the threshold (in ppm or Da) within which the neutral mass must lie to constitute a match.
Retention time within
Choose the threshold (in minutes or %) within which the retention time must lie to constitute a match. Can be turned on or off using the checkbox.
CCS within
Choose the threshold (in % or Å2) within which the CCS must lie to constitute a match. Can be turned on or off using the checkbox. Will be disabled if the experiment contains no CCS data.
Additional compound properties source
Allows you to load additional compound properties (e.g. RT and CCS) from an external file. See What are additional compound properties files? for more information.
Fragment search method
Allows you to choose between no fragmentation search, search against theoretical fragmentation, or search against a fragment database. See What are fragment databases? for more information.

After entering your search parameters, click Save search parameters to save your search parameter set for use in this and future experiments.

SDF Files

The SDF format contains structural information and other associated data about the metabolites in the database.

Here are some good sources of metabolite SDF databases which can be searched with MetaScope:

Excel File Format

If you are using a .CSV, .XLS or .XLSX file for MetaScope identifications, it should contain the following fields:

Field Name Required?
Neutral Mass Yes
Compound Id Yes
Description No
Formula No
Url No
Retention Time (min) If Retention time within checked.

Field names are case insensitive and can occur in any order.

You can also download an example database.

Note: you will need to have Microsoft Excel 2007 (or later) installed to perform the search.

See also