ProteoCool Pills#5: Safe Comassie blue staining solutions (compatible with microwave coloration)

 

After SDS-polyacrylamide gel elettrophoresis proteins are "fixed" in the gel to prevent dispersion of the proteins and visualized by staining with a chromogenic dye.

Until some years ago the dyes like Coomassie Blue R-250, were usually dissolved in an acetic acid-methanol-water mixture where acetic acid and methanol provide an environment enhancing the interactions with dyes when you are using standard room temperature staining/destaining protocol.

https://pubmed.ncbi.nlm.nih.gov/30097924/

To speed up the procedure, heating the staining solution in the microwave oven for a short time is frequently used (see ProteoCool n° 6;

https://www.blogger.com/video.g?token=AD6v5dwhmY5GkO9_ezq3Va_Tfqi6u0ys99hBWy2OxXI0esS7px1EdB64LQXElfRjWFrifwHtPdDxUERBgln233r-2MAurJXhLDWcqkP1X5Gr1gSvjYZLKNS5fdeNossEHQrrnebrxiHw)

Staining/destaining which microwave is not feasible with the standard dye acetic acid-methanol-water formulation due to evaporation of hazardous Methanol coupled with the strong smell of acetic acid in the lab which should be avoided due to environmental and safety considerations.

In the last 10 years many different water methanol/acid free formulations (which in some cases contain a small % of ethanol) where developed for staining of SDS-page gel using microwave.

I had the opportunity to use some commercially available products:

1)    PRoBLue – Giotto biotech – https://www.giottobiotech.com/prodotto/problue-safe-stain-2/ 

Its my first choice!   Strong blue colour, medium cost; 50euro/liter

 

2)    SimplyBlue™ SafeStain - https://www.thermofisher.com/order/catalog/product/LC6065?SID=srch-srp-LC6065#/LC6065?SID=srch-srp-LC6065

 

Weaker blue colour  à staining time respect than Problue to reach a good coloration most expensive à >100euro/liter

Many other suppliers (eg BIorad) sell similar water based Comassie Blue stain, but I never add the opportunity to test in with microwave approach.