Quantitative Western Blot: Separate Target Scans Experiment

Use the Separate Target Scan (STS) workflow when you need to analyze bands on blot images that were acquired in independent scans. Note: This Experiment type is for analyzing bands. Experiments involving a total protein stain should be analyzed using one of the total protein stain Experiment workflows.

Bands from independent scans cannot always be analyzed and compared accurately. See All About Images in Empiria Studio® Software for information about how separate target scans are performed and for guidance on when to avoid analyzing bands on images generated in separate target scans.

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 proteins 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.

Specify replicate lanes

The Specify replicate lanes page allows you to link replicate lanes for analysis. The numbered rectangles displayed on the page correspond to the lanes on your blot.

Add lane details

Record important details about your samples.

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 bands

Click Find Bands or Add to quantify bands. Bands enclosed by band boxes will be quantified.

The Next button will not be active until you have identified a band in each lane for at least one of the proteins (excluding lanes that you marked as Not Used or MW Marker on the Add lane details page).

Define lanes

In the STS workflow, the second Define lanes page enables you to adjust the size and placement of lanes on target images separately from lanes on the internal loading control image. See the first Define lanes section for general information about lane finding, including information about Auto mode vs Manual mode.

When adjusting lanes for target images, the number of lanes must remain the same for target bands to be associated correctly with an internal loading control. If you are using Auto mode and a different number of lanes are found for the target images than the number of lanes defined for the internal loading control, the Lane Number Error message will appear.

Lane Number Error: Could not find the same number of lanes on the target image and total protein stain image. Ensure the boundary encloses all the lanes on the image. Manual mode can also be used to define lanes.
Figure 191. The Lane Number Error indicates that a different number of lanes were found for the target images compared to the number of lanes defined for the internal loading control (i.e., on the first Define lanes page).

Review lane details

Use this page to double check the lane details. If you need to make a change, return to the Add lane details 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

Click Find Bands or Add to quantify bands. Bands enclosed by shapes will be quantified.

The Next button will not be active until you have identified a band in each lane for at least one of the proteins (excluding lanes that you marked as Not Used or MW Marker on the Add lane details page).

Set up calculations

The Set up calculations page allows you to choose how fold change (or percent change) is calculated for normalized signal values, and allows you to set up how the chart will appear when it is exported.

See Blot Quantification or Blot Quantification for more information about how values on this page are calculated.

Begin by selecting options in the table at the top of the page. Select the control and samples to include in the chart.

Review and report

The Review and report page allows you to export a PDF report of the entire Target Analysis, or you can export individual images and data tables.

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.