In addition to loading and displaying the peptides and proteins identified in an MS2 run, LabKey Server lets you associate experimental annotations, which can then be pulled into the various grid views. You can display and query things like sample properties and the experimental protocol.
Load Sample TypesSample types
contain a group of samples and properties for those samples. In the context of an MS2 experiment, these are generally the samples that are used as inputs to the mass spectrometer, often after they have been processed in some way.
Sample types defined in a particular project are scoped to that project; sample types defined in the Shared project
are available site-wide. Within a project, you can reference sample types that are in other folders under the same project, or sample types in the "Shared" project.
To set up a sample type, first navigate to a target folder. In an MS2 folder, there will be a Sample Types
web part present by default. It will show all of the existing sample types that are available in that folder.
If the sample type you want is not already defined, you will need to add and populate it. The easiest way to do this is to use a spreadsheet like Excel where one column is named Name
and contains the unique ID of each sample. The other columns should be properties of interest (the age of the participant, the type of cancer, the type of the sample, etc).
Follow the instructions in this topic to define a new sample type: Create Sample Type
Once the sample type is listed, click to open it, then click Import More Samples
. Learn about importing samples here: Import Samples
Describe mzXML Files
The next step is to tie mzXML files to samples. LabKey Server will prompt you to do this when you initiate an MS2 search through the pipeline.
Go to the Pipeline
tab or the pipeline section of the MS2 dashboard and click Process and Upload Data
. Browse to the mzXML file(s) you want to search. Click Describe Samples
If you've already described the mzXML files, you have the option to delete the existing information and enter the data again. This is useful if you made a mistake when entering the data the first time or want to make other changes.
If you haven't already created a protocol for your experimental procedure, click create a new protocol
. Depending on your configuration, you may be given a list of templates from which to start. For example, you may have worked with someone at LabKey to create a custom protocol to describe a particular fractionation approach. Select a template, if needed, and fill in a description of the protocol.
Then select the relevant protocol from the list. If you started from a directory that contains multiple mzXML files, you will need to indicate if the mzXML files represent fractions of a larger sample.
The next screen asks you to identify the samples that were inputs to the mass spectrometer. The active sample type for the current LabKey Server folder, if any, is selected as the default. It is strongly recommended that you use the active sample type or no sample type. You can change the default name for the runs. For each run, you are asked for the Material Sample ID. You can use the text box to type in a name if it is not part of a sample type. Otherwise, choose the name of the sample from the drop down.
Once you click Submit
, LabKey Server will create a XAR file that includes the information you entered and load it in the background.
Kick Off an MS2 Search
To initiate an MS2 search, return to the Data Pipeline, select the mzXML files, and initate the search type you want. Learn more in this topic: Search and Process MS2 Data
View Annotation Data
Experimental annotations relating to a particular file or sample are stored as an experiment run
. Each experiment run has a protocol
, which describes the steps involved in the experimental procedure. For MS2, LabKey Server creates an experiment run that describes going from a sample to one or more mzXML files. Each time you do a search using the mzXML files creates another experiment run. LabKey Server can tie the two types of runs because it knows that the output of the first run, the mzXML files, are the inputs to the search run.
You can see the sample data associated with a search run using the "Enhanced MS2 Run" view, or by selecting the "MS2 Searches" filter in the Experiment tab's run list. This will only show MS2 runs that have experimental data loaded. In some cases, such as if you moved MS2 runs from another folder, or if you directly loaded a pep.xml file, no experimental data will be loaded.
- Select (Grid Views) > Customize Grid.
- Scroll down and click to expand the Input node. This shows all the things that might be inputs to a run in the current folder.
- Click to expand the mzXML node. This shows data for the mzXML file that was an input to the search run.
- Click to expand the Run node. This shows the data that's available for the experiment run that produced the mzXML file.
- Click to expand the Input node. This shows the things that might be inputs to the run that produced the mzXML file.
- If you used a custom template to describe your mass spectrometer configuration, you should expand the node that corresponds to that protocol's inputs.
- Otherwise, click to expand the Material node.
- Click to expand the Property node, which will show the properties from the folder's active sample type.
- Click to add the columns of interest, and then Save the column list.
You can then filter and sort the run on the sample properties you added.
You can also pull in sample information in the peptides/proteins grids by using the new Query grouping. Use the grid view customizer to go to Fraction > Run > Experiment Run. Follow the instructions above to chain through the inputs and get to sample properties.