It’s a pretty well-known fact that the different science spheres have their own lingo. An immunologist and a biochemist will often require an interpreter just to understand one another.
Different techniques can also have their own language – one that is used to describe and interpret the data.
To help you speak the language of quantitative Western blots, we have compiled a dictionary of Western blot lingo.
Limit of detection
The minimum amount of protein that can be detected (usually by an antibody). Highly sensitive antibodies will decrease the limit of detection.
It can be hard to find a good antibody, this is a time when spending the money might be worth it to buy an antibody that has a low limit of detection.
Limit of quantitation
The minimum amount of protein that can be quantified; usually defined by the signal to noise ratio.
Do everything you can to get that background down – high background will severely hurt your limit of quantitation. See our solutions to high background here and here.
Signal to noise ratio
A comparison of the level of the specific signal to the level of background noise.
No, you can’t fix the ratio by using different exposure times.
Linear dynamic range
The range in which the signal intensity is proportional to the protein quantity on the blot. The dynamic range is affected by the limit of detection and sensitivity of the antibody.
Straight lines are important guys!
CCD
Charge-coupled device; often the device is a camera. A CCD stores and displays the data for an image by converting each pixel in the image into an electrical charge. The intensity of the charge is related to a color on the color spectrum. CCDs are major devices for high-resolution digital imaging of light-producing reactions.
Otherwise known as the box you need to use in the neighboring lab.
Densitometry
The measurement of optical density in a light-sensitive material due to exposure to light. Used to measure and express the amount of signal in a band.
Don’t be dense – make sure you get lessons in how to use densitometry to measure protein amounts.
So now you shouldn’t have any problem chatting with people using the right Western blot lingo. Don’t ask me to help you with immunology though!
Photo courtesy of CHRIS DRUMM.
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