Profiles of five programs for quantifying data from Westerns, dot blots, gels, and colony cultures
When you’re looking at bands on a Western blot, it’s often obvious which lane has a lot of protein or a little. But it’s not always easy to tell with the naked eye precisely how two bands compare. Plus, looks can deceive. For example, if a lane widened or a band developed a “smile” as the gel ran, a protein-heavy band might look faint.
That’s where imaging software can help, by putting numbers on the density of a band. Just draw a box around your band and the program will tell you the pixel density. Some programs do much more, such as quantifying the number of colonies on a petri dish or the intensity of fluorescent signals in a 96-well plate. “It’s just an improvement on the eyeball,” says Jeff Silk, president of Silk Scientific, in Orem, Utah, which sells gel analysis software.
Researchers have plenty of options for software to bolster their own vision, ranging from freebies that work with any type of image to expensive programs or ones that are specific to their imaging machinery. Unlike Photoshop or other general image-editing software, these dedicated programs can often automatically detect where each lane starts and ends or sum up multiple bands. They can also winnow away background signal, which arises from a variety of causes such as nonspecific binding of antibodies to the entire blot or overexposure when imaging.
Read more: Software for Image Analysis
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Source: the-scientist
