Quantitative Western Blot: TPS + Targets Linear Range Workflow

This workflow will help you identify, if possible, the combined linear range The range of sample loading that produces a linear response between sample loading and signal intensity -- for both the target and internal loading control. for your targets and a total protein stain.

Name

To help with record-keeping, give every Experiment a distinct name. The description field provides space for you to include important details about the Experiment.

Set up images

Ensure the correct images have been chosen, then enter information for the total protein stain and protein targets that are being analyzed.

Click the zoom buttons above the image to make the displayed image smaller or larger . A zoom level, shown as a percentage relative to the size of the software window, is shown next to the zoom buttons.

Define lanes

The Define lanes page identifies lanes on the image for analysis. To find lanes, draw a boundary that encloses all the lanes on the image.

By default, Auto mode automatically performs lane finding. Manual mode is also available.

Add lane details

At least three unique values must be specified in the Amounts fields to progress past this page. Remember, a dilution series is required to determine the relationship between sample loading and signal.

  • Name: Provide a lane name to facilitate record keeping and organization.

  • Type: Specify the appropriate type for each lane.

    • MW Marker: Choose MW Marker for all lanes that contain a molecular weight marker.

      Designate marker lanes now to size bands at a later step in the analysis.

    • Sample: Choose Sample for lanes that are part of the dilution series that will be used to determine linear range.

    • Not Used: Choose Not Used for lanes you do not want to include in your analysis. For example, you might choose Not Used if a lane is empty. Empiria Studio will not find bands in lanes marked Not Used.

  • Value Label: Indicate amount under the dropdown menu and the associated unit for each sample lane in the dilution series.

    Click the Autofill button to see options for quickly filling out the table.

Assign MW marker

Assign a molecular weight marker to estimate the molecular weight of bands. Estimated molecular weights will be available in the Analysis Table of the Quantify bands page.

Quantify lanes

The lane rectangles on this page are created based on the lanes defined on the Define lanes page. The quantification value for lanes can be viewed in the Analysis Table on this page. If lanes were defined using Manual mode, the size and placement of lane rectangles can be adjusted if necessary.

Define lanes

  • If Auto mode was used to define lanes, the boundary can be adjusted if necessary.
  • If Manual mode was used to define lanes, the size and placement of lane rectangles can be adjusted if necessary.

Review lane details

By default, the Review lane details page shows the sample details you entered for the total protein stain. If you need to change a sample type designation or sample loading amount for your target, do so on this page.

Assign MW marker

Assign a molecular weight marker to estimate the molecular weight of bands. Estimated molecular weights will be available in the Analysis Table of the Quantify bands page.

You can estimate the molecular weight of target bands in one channel using a marker in another channel when you link a Band Channel to a Marker Channel.

Quantify bands

The Next button will not be active until you have identified a band in each lane (aside from lanes that you marked as Not Used or MW Marker on the Add lane details page).

Find combined linear range

The graph on this page shows the relationship between sample loading and signal intensity for both the total protein stain and target.

Overlapping regions of linearity are the combined linear range The range of sample loading that produces a linear response between sample loading and signal intensity -- for both the target and internal loading control.. Combined linear ranges are where the bar for both total protein stain and target are green (excellent linearity) or yellow (good linearity). Red indicates regions of no linearity.

The median of the combined linear range is usually a good place to start when deciding how much protein to load, but it is up to the researcher to make a final determination about how much protein to load.

Review and report

The Review and report page allows you to record your observations and conclusions in the Summary field for future reference. Export individual images and data tables or export a PDF file containing the data and images.

The data in the report is organized into sections. Click to expand a section to view data and export options.

Done

Click Done to mark this Experiment as complete and return to the Experiment List.