What’s your quantitative western blotting IQ?
Are you doing everything you should to ensure accurate quantitative western blot data? Find out by testing yourself with this quantitative western blotting quiz. If you get one or more questions wrong, you can brush up on the basics by downloading our Quantitative Western Blotting Basics guidebook using the form on the right.
1. True or False: To get quantitative western blotting data do the following:
- Follow your typical western blotting protocol. Be sure to probe for your protein-of-interest and a housekeeping protein so you can normalize your data
- Image the blot on a digital imager
- Draw boxes around the bands of your protein-of-interest and your housekeeping protein and use the imager to generate a number for band intensity. Follow your imager’s instructions for subtracting background
- Calculate the ratio of your protein-of-interest to housekeeping protein to obtain relative protein abundance
2. True or False: You must use fluorescently-labeled antibodies to get quantitative western blotting data.
3. Which of the following methods can you use to validate an antibody for quantitative western blotting:
A. Genetic method: Show that when the amount of your protein-of-interest is reduced, the signal from your antibody used in an ELISA assay is also reduced.
B. Orthogonal method: Show that measurement of protein abundance using your antibody correlates strongly with the measurement of protein abundance using an orthogonal method such as mass spectrometry.
C. Independent antibody: Show that the measurement of protein abundance using your antibody correlates strongly with the measurement of protein abundance using a second, already validated antibody.
4. True or False: The best way to normalize western blot data is to use a housekeeping protein?
5. Which of the following parts of the western blotting workflow should be tested to ensure that your experimental conditions are not causing the signal to saturate:
Want an overview of all the steps you need to take to get quantitative data from your westerns? Use the form above to download a PDF of our Quantitative Western Blotting Basics guidebook.
1. Janes KA. An analysis of critical factors for quantitative immunoblotting. Sci Signaling. 2015 Apr 7;8(371):rs2. PMCID: PMC4401487.
2. Uhlen M, et al. A proposal for validation of antibodies. Nat Methods. 2016 Oct;13(10):823-7. PMID: 27595404.