If you have a flow cytometry experiment containing a background control (such as an unstimulated sample, an unstained sample, or a Fluorescence Minus One (FMO) control), you can set the background in LabKey for use in analysis. To perform this step we need to:
  • Identify the background controls
  • Associate the background values with their corresponding samples of interest
This tutorial shows you how to associate sample descriptions with flow data, define and set new keywords, and set metadata including background information. Positive and negative responses can then be calculated against this background.

To gain familiarity with the basics of the flow dashboard, data grids, and using graphs, you can complete the Tutorial: Import a Flow Workspace first. It uses the same setup and sample data as this tutorial.

Tutorial Steps:

Set Up

To set up a "Flow Tutorial" folder, complete the instructions in this topic, if you did not already do so:

Upload Sample Descriptions

Sample descriptions give the flow module information about how to interpret a group of FCS files using keywords.

  • Click the Flow Tutorial link or use the project menu to go to the main page of your flow tutorial folder. This is your flow dashboard.
  • Click Upload Samples (under Manage).
  • You can either enter data directly into the window or upload a file. For this tutorial, download, then upload this file:
  • Name Format: Identify how the unique key for this set will be generated. Options:
    • Expression: Enter an expression to format the ID.
    • ID Columns: Select the format columns (shown here, the "TubeName" column).
  • Select a Parent Column if needed.
  • Click Submit.

Once it is uploaded, you will see the sample set.

Associate the Sample Set Descriptions with the FCS Files

  • Return to the main dashboard by clicking the Flow Tutorial link near the top of the page.
  • Click Define Sample Description Join Fields.
  • On the Join Samples page, set how the properties of the sample set should be mapped to the keywords in the FCS files.
  • For this tutorial, select TubeName from the Sample Property menu, and Name from the FCS Property menu
  • Click Update.

You will see how many FCS Files could be linked to samples in the given sample set. To see the grid of which samples were linked to which files, click the Flow Tutorial link, then the link showing the number of sample descriptions (under "Assign additional meanings to keywords").

Add Keywords as Needed

Keywords imported from FlowJo can be used to link samples, as shown above. If you want to add additional information within LabKey, you can do so using additional keywords.

  • Return to the main Flow Tutorial dashboard and click the number of FCS files.
  • Select the rows to which you want to add a keyword and set a value. For this tutorial, click the box at the top of the column to select all rows.
  • Click Edit Keywords.
  • You will see the list of existing keywords.
    • The blank boxes in the righthand column provide an opportunity to change the values of exisitng keywords. If you leave the boxes blank, no changes will be made to the existing data.
    • For this tutorial, make no changes to the existing keyword values.
  • Click Create a new keyword to add a new keyword for the selected rows.
  • Enter "SampleType" as the keyword, and "Blood" as the value.
  • Click Update.
  • You will see the new SampleType column in the files data grid, with all (selected) rows set to "Blood".

If some of the samples were of another type, you could repeat the "Edit Keywords" process for the subset of rows of that other type, entering the same "SampleType" keyword and the alternate value.

Set Metadata

Setting metadata including participant and visit information for samples makes it possible to integrate flow data with other data about those participants.

Background and foreground match columns are used to identify the group -- using subject and timepoint is one option.

Background setting: it is used to identify which well or wells are background out of the group of wells. If more than one well is identified as background in the group, the background value will be averaged.

  • Click the Flow Tutorial link near the top of the page to return to the main flow dashboard.
  • Click Edit Metadata.
  • On the Edit Metadata page, you can set three categories of metadata. Be sure to click Save Metadata at the bottom of the page.

  • Sample Columns: Select how to identify your samples. There are two options:
    • Set the Specimen ID column or
    • Set the Participant column and set either a Visit column or Date column.


  • Background and Foreground Match Columns
    • Select the columns that match between both the foreground and background wells.
    • You can select columns from the uploaded data, sample set, and keywords simultaneously as needed. Here we choose the participant ID since there is a distinct baseline for each participant we want to use.


  • Background Column, Operator, and Value
    • Specify the column and how to filter the values to uniquely identify the background wells from the foreground wells.
    • Here, we choose the "Sample WellType" column, and declare rows where the well type "Contains" "Baseline" as the background.
  • When finished, click Set Metadata.

Use Background Information

  • Click the Flow Tutorial link near the top of the page to return to the main flow dashboard.
  • Click the Analysis Folder you want to view, here Analysis (1 run).
  • Click the name ADemoWorkspace.wsp to open the grid of workspace data.
  • Notice the columns prefixed with "BG" that are shown. These are the background values that can be compared against the non background data.

After setting metadata, you may need to wait for background values to be calculated. If you don't see them in the next step, wait and refresh the page. If you still don't see them, you may need an admin to clear and refresh the cache.

Control which columns are visible using the standard grid customization interface, which will include a node for background values once the metadata is set.

  • Select (Grid Views) > Customize Grid.
  • Now you will see a node for Background.
  • Click the to expand it.
  • Use the checkboxes to control which columns are displayed.
  • To see the source of background data, open the FCSFile node and check the boxes for PTID and Well Type.
  • Click Save, then Save in the popup to save this grid view as the default.
  • Click the header for PTID and select Sort Ascending.
  • Now you can see that the data for each PTID's "Baseline" well is entered into the corresponding BG fields for all other wells for that participant.

Display graphs by selecting Show Graphs > Inline as shown here:

Congratulations

You have now completed the tutorial and can use this process with your own data to analyze data against your own defined background.

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