Coomassie Blue Staining Protocol - Standard Lab Procedures

Coomassie Blue Staining Protocol – Standard Lab Procedures

By: - Science - September 15, 2011
coomassie blue staining protocol %E2%80%93 standard lab procedures

If you are interested in learning more about Coomassie blue staining protocol you have come to the right place. Coomassie blue is a common textile dye that has been used for years. Recently it has become popular in analytical biochemistry as a way to stain proteins. In the present, it is being used in studies as part of a possible treatment for spinal injuries. In a lab, however, Coomassie blue isn’t that glamorous.

For standard Coomassie blue staining protocol, you will use the Coomassie Blue R-250. You will want to use a gel with 10% HoAC, 40% H2O and 50% MeOH. Prefix anywhere from 30 minutes to 8 hours. While in the solution, stain the gel with the R-250 0.25% Coomassie Blue. It should take from 2-4 hours to fully stain and the gel should be consistent in color. You will know it is completely stained when you cannot see the gel in the dye solution. Once the gel is completely dyed, you should transfer into a solution of 87.5% H2O, 5% MeOH, 7.5% HoAC. You should see bands of protein appearing within 2-4 hours.  To store the gel safely, put it in a solution of 7% HoAC.

The Coomassie blue staining protocol is now complete. There are also two different types of rapid protocols using Coomassie Blue R-250 where bands will appear in 15 to 30 minutes.

Another way to detect protein on gel besides Coomassie blue is to use silver staining. Silver staining protocol is quite easy in a lab and will detect protein like the Coomassie blue. Here is an example of a rapid silver staining protocol:

Soak the gel for about 10 minutes in a fixing solution (40% methanol and 13.5% formalin). Wash the gel twice, 5 minutes each wash.  Once the second wash is complete, soak gel in 0.02% Na2S2O3 for 1 minute then wash in water two times, 20 seconds each. Again, after the second wash, soak the gel in 0.1% AgNO3. You then want to wash in water with a small bit of developing solution (3% sodium carbonate, 0.05% formalin and 0.000016% Na2S2O3). You should begin seeing the bands forming. You will then just let the gel soak in developing solution with formalin fresh. Add a drop or two of citric acid and you will see further band development. Wash gel in water for 10 minutes then soak for 30 minutes in water to finish up the silver staining protocol.