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Thermo Scientific™ Spectra™ Multicolor High Range Protein Ladder
Description
Thermo Scientific™ Spectra Multicolor High Range Protein Ladder is a mixture of eight (8) blue-, green and orange-stained proteins (40 to 300kDa) for use as size standards for high MW proteins in gel electrophoresis and Western blotting.
Highlights:
Size range – eight proteins spanning 40 to 300kDa
Multicolor – three different colors for unambiguous band-size assignment
Ready-to-use – supplied in a loading buffer for direct loading on gels; no need to boil
Sharp bands – color-coded bands of similar intensity for easy visualization
Quality tested – each lot evaluated by SDS-PAGE and Western blotting
Membrane-compatible – colored bands transfer to membranes for Western blotting
Includes:
Dye-stained proteins in 62.5mM Tris-H3PO4 (pH 7.5 at 25°C), 1mM EDTA, 2% SDS, 10mM DTT, 1mM NaN3 and 33% glycerol.
Recommended for:
Monitoring of protein migration during SDS-PAGE; Verifying Western transfer efficiency; Approximate sizing of proteins on SDS-polyacrylamide gels and Western blots; Locating a protein of interest for excision from an unstained preparative gel
Specifications
Specifications
| Content And Storage | Contents: two vials of 250 μL each Storage buffer: 62.5 mM Tris-H3PO4 (pH 7.5 at 25°C), 1 mM EDTA, 2% SDS, 10 mM DTT, 1 mM NaN3 and 33% glycerol Storage: Upon receipt store at -20°C |
| Detection Method | Colorimetric, NIR Fluorescence (700 nm), RGB Fluorescence (555 nm) |
| Number of Markers | 8 |
| Ready to Load | Yes |
| Recommended Applications | Tris-acetate gels |
| Size Range | 40 to 300 kDa |
| For Use With (Application) | Tris-acetate gels |
| Gel Compatibility | Bolt™ Bis-Tris Plus Gels, Novex™ Tricine Gels, Novex™ Tris-Glycine Gels, NuPAGE™ Bis-Tris Gels, NuPAGE™ Tris-Acetate Gels, SDS-PAGE Gels |
| Molecular Weight (g/mol) | 300, 250, 180, 130, 100, 70, 50, 40 kDa |
| Quantity | 2 x 250 μL |
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Frequently Asked Questions (FAQs)
Coupling of chromophores to proteins affects the apparent molecular weight of proteins in SDS-PAGE relative to unstained standards. The apparent molecular weight of prestained protein standards is calibrated in the classical TRIS glycine-SDS Laemmli system, however prestained proteins may have different mobility in other electrophoresis buffer and gel systems. It should also be noted that the sizing of proteins by gel electrophoresis does not give an exact value and depends on the protein sequence and post-modification.
The upper bands of the ladder may be degraded by proteases. Ladder, gel, buffer, pipettes, pipette tips, or equipment can be contaminated by proteases during usage. A general recommendation would be to avoid working with proteases in the same room. We would recommend preparing fresh solutions, cleaning the equipment, and using clean pipettes and tips. If the ladder itself is contaminated, please use a new tube of the ladder.
No, proteins in Thermo Scientific protein ladders are not His tagged. However, non-specific interaction between the ladder proteins and primary or secondary antibodies is possible and some His-Tag detection systems, such as Thermo Scientific 6xHis Protein Tag Stain Reagent Kit, show non-specific interaction. The protein ladder bands are more readily detected when using high antibody concentrations. The non-specific cross-reactivity is difficult to predict, it often has a different pattern dependent on the antibodies used in each individual experiment. The most general way to handle this problem would be to use lower concentrations of antibodies and to use lower amount of protein ladders. It may also be useful to leave one empty well between the ladder and the sample to overcome a possible leakage of the signal to the nearby sample lane.
PageRuler Unstained protein ladders can be detected directly on Western blots by using Strep-Tactin conjugates or an antibody against the Strep-tag II sequence. All PageRuler and Spectra ladder proteins contain an integral Strep-tag II sequence, however the prestained ladders cannot be detected by Strep-Tactin conjugates.
All PageRuler and Spectra ladder bands are recombinant prokaryotic proteins purified from E. coli cells. None of them are related to eukaryotic proteins, however this cannot exclude the possibility that the ladder proteins may possess an epitope that is cross-reactive with the antibody used.
For Research Use Only. Not for use in diagnostic procedures.