Determining Percent Purity
- Scan image and save as a tiff file (8-bit not 16-bit) with lanes oriented vertically.
- Open ImageJ either locally or via the webstart applet at http://rsbweb.nih.gov/ij/applets.html
- Using a rectangular box select entire lane.
- Select lane either by selecting Analyze->Gels->Select First Lane or CTRL-1
- Plot lane by selecting Analyze->Gels->Plot Lanes or CTRL-3
- Draw baseline using the line tool.
- If necessary use the line tool to connect peaks to the baseline
- Select peaks using the wand (tracing) tool
- Calculate purity by the area under the peak of interest divided by the area under all peaks combined.