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.
To set up a "Flow Tutorial" folder
, and import the sample data package, complete the instructions in this topic:
Upload Sample Descriptions
Sample descriptions give the flow module information about how to interpret a group of FCS files using keywords. The flow module uses a sample set named "Samples" which you must first define and structure correctly. Download this file to use:
- Navigate to your Flow Tutorial folder. This is your flow dashboard.
- Click Upload Samples (under Manage in the Flow Summary web part).
- You cannot edit the name "Samples".
- In the Name Expression field, enter this string to use the "TubeName" column as the unique identifier for this sample set.
- You don't need to add a Description or set a parent column import alias.
- Click Create.
- On the next panel, click Infer Fields From File.
- In the popup, choose the "SampleSetDemo.xls" file you downloaded, then click Submit.
- The fields shown in the screencap below will be inferred.
- You could also individually add these fields using the Add Field option, adjusting the types by hand.
You will return to the main flow dashboard, having defined the sample set you need. You will upload the actual sample information next.
- In the Flow Tutorial folder, click Upload Samples.
- You can either enter data directly into the window or upload a file. For this tutorial, click Upload File.
- Leave the Insert option selected.
- Click Browse to locate and select the "SampleSetDemo.xlsx" file you downloaded.
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 in the Flow Experiment Management web part.
- 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
You will see how many FCS Files could be linked to samples in the given sample set. The number of files linked to samples may be different from the number of sample descriptions since multiple files can be linked to any given sample. 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 found under item 1 in the Flow Experiment Management web part.
- 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.
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.
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), in the Flow Summary web part.
- 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.
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 icon to expand it.
- Use the checkboxes to control which columns are displayed.
- To see the source of background data, open the FCSFile node, then the Sample 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:
You have now completed the tutorial and can use this process with your own data to analyze data against your own defined background.