Thermo Scientific Spectra Multicolor Low Range Protein Ladder is a mixture of six (6) proteins and synthetic peptides (1.7 to 40kDa) for use as size standards for peptides and small proteins in gel electrophoresis and Western blotting.
This prestained protein MW marker is designed for monitoring the progress of SDS-polyacrylamide gel electrophoresis, for assessing transfer efficiency onto PVDF, nylon and nitrocellulose membranes, and for estimating the approximate size of separated proteins that have been made visible with gel stains or Western blot detection reagents. Three different chromophores (blue, orange, green) are bound to the different component proteins, producing a brightly colored ladder with an easy-to-remember pattern. The Spectra Multicolor High Range Protein Ladder is ready to use: no heating, further dilution or addition of a reducing agent is required.
- Size range – six proteins and peptides spanning 1.7 to 40kDa
- 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
- 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.
- 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
SDS-PAGE band profile of the Thermo Scientific Spectra Multicolor Low Range Protein Ladder. Images are from an 18% Tris-tricine small-peptide SDS-polyacrylamide gel with 5% crosslinking, and subsequent transfer to membrane.
Migration patterns of Spectra Multicolor Low Range Protein Ladder in different electrophoretic conditions. The apparent molecular weight of each protein (kDa) has been determined by calibration of each protein against an unstained protein ladder in specific electrophoresis conditions. Migration patterns were determined using commercial precast mini gels. SP refers to small peptide SDS-polyacrylamide gels with a higher degree of crosslinking (c=5% instead of usual ~3%).
- Laemmli, U.K. (1970). Cleavage of structural proteins during the assembly of the head of bacteriophage T4, Nature, 227, 680-685.
- Burnette, W.N. (1981). Western blotting: electrophoretic transfer of proteins from sodium dodecyl sulfate – polyacrylamide gels to unmodified nitrocellulose and radiographic detection with antibody and radioiodinated protein A, Anal. Biochem., 112 (2), 195-203.
- Towbin, H., et al. (1979). Electrophoretic transfer of proteins from polyacrylamide gels to nitrocellulose sheets: procedure and some applications, Proc. Natl. Acad. Sci. USA, 76, 4350-4354.
- Kurien, B.T. and Scofield, R.H. (2003). Protein blotting: a review, J. Imm. Meth., 274, 1-15.
Protein Molecular Weight Markers – product comparison and selection guide
Protein Gel Stains and Kits – compare colorimetric and fluorescent gel stains
Precise Protein Gels – browse all pre-cast gels for SDS-PAGE
BupH Dry Blend Electrophoresis Buffers – Tris-HEPES-SDS and other pouched electrophoresis buffers
Reducing Agents – 2-mercaptoethanol, DTT, TCEP and other reducing agents
Western blotting substrates and reagents – find kits, stripping buffers, blotting membranes and film