New England Biolabs, P7717S, Unstained Protein Standard, Broad Range (10-200 kDa)

The Unstained Protein Standard, Broad Range is a mixture of highly pure, recombinant proteins that resolves into 13 sharp bands from 10-200 kDa when electrophoresed and stained with Coomassie Brilliant Blue R-250 or other commercially available, ready-to-use protein stains. Related Categories Protein Standards,, Markers & Ladders,, Protein Standards Applications Protein Standards,, Protein Analysis Tools Specification Storage Buffer 62.5 mM Tris-phosphate 1 mM EDTA 2% SDS 10 mM DTT 1 mM NaN3 0.01% bromophenol blue 33% Glycerol pH 7.5 @ -20°C FAQ Q: How does the Unstained Protein Standard, Broad Range differ from NEB’s previous Unstained Protein Standard? A: The new Unstained Protein Standard (NEB #P7717) can be used as a direct replacement for the previous Unstained Protein Standard (NEB #P7704). The proteins used in the new Unstained Protein Standard are different than those used in the previous Unstained Protein Standard, thus it is important to note that the apparent molecular weights will be slightly different. The new Unstained Protein Standard contains 13 proteins ranging in molecular weight from 10 – 200 kDa; whereas, the previous Unstained Protein Standard contained only 12 proteins in the same molecular weight range. Q: What is the protein concentration of the proteins used in the Unstained Protein Standard, Broad Range? A: The overall protein concentration of the Unstained Protein Standard, Broad Range is approximately 2.0 mg/ml. However, this is merely an estimate. We do not recommend using this or any protein standard as a tool for precise quantitation of protein concentration. These products are meant to estimate protein molecular weight. Q: Can the Unstained Protein Standard, Broad Range be used as a precise standard for determining the exact molecular weight of a protein of interest? A: Molecular weight determination by SDS-PAGE is a dependable method. However, an unknown protein’s molecular weight should be obtained by mass spectrometry if a precise molecular weight determination is required. Mass spectrometry has a higher degree of accuracy because each amino acid of a protein is analyzed. Q: Is the Unstained Protein Standard, Broad Range compatible with various methods of staining, such as SYPRO® Ruby Protein Gel Stain or Silver Staining? A: Yes, the Unstained Protein Standard, Broad Range is compatible with various staining techniques such as SYPRO Ruby Protein Gel and silver staining. These methods of staining are highly sensitive and require a lower load volume, as low as 1 µl, of Unstained Protein Standard, Broad Range for visualization on a gel. Q: I accidentally left my Protein Standard out at room temperature for a number of days. Is it still okay to use? A: Stability testing has shown that NEB’s Protein Standards will remain stable for up to 2 weeks at room temperature (25°C) and for up to 1 year at 4°C. We do not, however, recommend storing your Protein Standard at anything other than optimal storage temperature, which is -20°C, for a guaranteed shelf life of 2 years.