The staining of proteins following PAGE separation can be a time-consuming, labor-intensive process. However, Fermentas’ Page Blue Protein Stain effectively cuts down on the time for fixing, staining and de-staining gels. The PageBlue stain is a single, ready-to-use reagent that can rapidly detect low levels of protein. It is based on the Coomassie protocol but offers increased sensitivity, similar to SYPRO Ruby, detecting as little as 5 ng of protein. The dye forms colloidal particles with proteins that are preferentially stained, without significant background on the gel matrix. In addition, the solution offers end point staining, preventing overstaining regardless of how long the gel is incubated. In addition, the gels can be stored in deionized water, a feature that is particularly useful for rapid staining (total time is 25 min for native gels and 40 min for SDS gels). Even the suggested conventional technique is rapid compared with other staining solutions I have used (65 min for native gels and 95 min for SDS gels). The detection is rapid and produces distinct, sharp bands.
According to the product literature, the linear dynamic range of Page Blue extends over two orders of magnitude (from 5 to 500 ng), which is superior to Coomassie. This stain stands out among other staining solutions because it is safe and it does not contain toxic methanol or acetic acid, making the waste disposal environmental-friendly. This feature is very important for me and many others who have intolerance to methanol or acetic acid. I used Page blue to visualize proteins separated on both minigels and large gels for 2-D electrophoresis from leg extensor neuromuscular junction axons. I found that the better contrast due to minimal background compensate the reduced colour intensity (blue) compared with Coomassie (dark blue) and used it with similar results to isolate protein stained bands or spots that I further sent to Mass spectrometry for protein identification.
Moreover, the solution offers versatility, staining conventional or pre-cast native, SDS and IEF gels and blotting membranes, and is compatible with various electrophoresis buffer formulations. The stain is also compatible with mass spectrometry and silver staining. The staining solution is also economical, as it can be re-used up to three times without a noticeable decrease in sensitivity and is much cheaper than SYPRO Ruby (that can be re-used once with diminished results).
The protocol is fast and easy to follow, requiring very little hands on time. All steps are conducted at room temperature and require the addition of deionized water for washing steps.
Dr. Lorelei Silverman
Department Physiology
University of Toronto