Description
GoldBio's BLUEstain™ Low Range Protein Ladder is a ready-to-use, tri-color prestained protein standard containing six recombinant protein bands ranging from 2 to 40 kDa.
It is designed for approximate molecular weight estimation of low molecular weight proteins while allowing researchers to monitor protein separation during SDS-PAGE and confirm that electrophoretic transfer to a Western blot membrane has occurred.
The ladder is compatible with Tris-Tricine, Tris-Glycine, and Bis-Tris gel systems, although the apparent migration of prestained bands may vary somewhat between gel chemistries.
Two colored reference bands simplify gel interpretation and membrane orientation, allowing you to quickly identify key molecular weight markers during electrophoresis and protein transfer.
Clearly visible reference bands below 10 kDa make this ladder especially useful for monitoring and estimating the apparent sizes of small proteins, peptides, and other low molecular weight samples.
The ladder is supplied in a ready-to-use loading buffer containing Tris-phosphate, SDS, dithiothreitol (DTT), urea, and glycerol for consistent migration and long-term stability.
Features
- Ready-to-use! No dilutions necessary.
- Two reference bands — 40 kDa (red) and 10 kDa (green).
- Enhanced band clarity for proteins below 10 kDa.
- Versatile application across various gel systems, including Tris-Tricine, Tris-Glycine, and Bis-Tris gels.
- 3 μl or 5 μl per loading for clear visualization during electrophoresis on 15-well or 10-well mini-gel, respectively.
- 1.5~2.5 μl per well for general Western transferring.
- Apply more for thicker (>1.5 mm) or larger gel.
Contents
Approximately 0.1~0.4 mg/ml of each protein in the buffer (20mM Tris-phosphate, pH 7.5 at 25°C, 2% SDS, 10mM Dithiothreitol, 3.6 M Urea, and 15% (v/v) Glycerol).
Common Applications
(Click each for more information)
Molecular Weight Estimation by SDS-PAGE
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Purpose: To estimate the molecular weight of unknown proteins following electrophoretic separation.
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How It Works: The ladder contains six prestained protein standards with reference molecular weights ranging from 2 to 40 kDa. When run alongside experimental samples, the bands provide reference points for approximating protein size within the selected gel system.
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Applications: Protein expression analysis, recombinant protein purification, protein characterization, and routine SDS-PAGE experiments.
Laemmli, U. K. (1970). Cleavage of structural proteins during the assembly of the head of bacteriophage T4. Nature, 227(5259), 680–685.
Western Blot Transfer Monitoring
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Purpose: To monitor electrophoretic transfer and confirm the orientation of proteins transferred from a polyacrylamide gel to a blotting membrane.
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How It Works: Prestained ladder bands remain visible during electrophoresis and transfer, allowing researchers to confirm ladder transfer, assess membrane orientation, and identify the approximate positions of molecular weight markers before immunodetection.
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Applications: Western blotting, immunoblot development, transfer optimization, and membrane quality control.
Towbin, H., Staehelin, T., & Gordon, J. (1979). Electrophoretic transfer of proteins from polyacrylamide gels to nitrocellulose sheets: Procedure and some applications. Proceedings of the National Academy of Sciences, 76(9), 4350–4354.
Low Molecular Weight Protein and Peptide Analysis
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Purpose: To approximate the apparent molecular weights of small proteins and peptides during electrophoretic separation.
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How It Works: The ladder provides visible reference bands spanning 2 to 40 kDa, including markers below 10 kDa, for comparison with low molecular weight proteins separated on an appropriate gel system.
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Applications: Small-protein analysis, recombinant peptide purification, low molecular weight protein characterization, and evaluation of protein fragments.
Schägger, H., & von Jagow, G. (1987). Tricine-sodium dodecyl sulfate-polyacrylamide gel electrophoresis for the separation of proteins in the range from 1 to 100 kDa. Analytical Biochemistry, 166(2), 368–379.
Monitoring Protein Electrophoresis
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Purpose: To observe protein migration and determine when electrophoresis is complete.
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How It Works: Prestained protein bands migrate during electrophoresis, providing a visible indicator of protein separation and run progress without requiring post-run staining.
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Applications: Routine SDS-PAGE, protein purification workflows, teaching laboratories, and electrophoresis optimization.
Gallagher, S. R. (2012). One-dimensional SDS gel electrophoresis of proteins. Current Protocols in Molecular Biology, Chapter 10, Unit 10.2.
Quality Control During Protein Analysis
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Purpose: To provide a consistent molecular weight reference for reproducible protein analysis.
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How It Works: Running the ladder with every gel establishes known molecular weight standards, helping verify gel performance, protein migration, and experimental consistency.
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Applications: Laboratory quality control, assay validation, method development, and reproducible protein analysis.
Gallagher, S. R. (2012). One-dimensional SDS gel electrophoresis of proteins. Current Protocols in Molecular Biology, Chapter 10, Unit 10.2A.
Key Benefits
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Ready-to-Use Format: Supplied in loading buffer for direct application to SDS-PAGE gels. No dilution, heating, or reducing agent is required before use.
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Optimized for Low Molecular Weight Proteins: Protein bands spanning 2 to 40 kDa provide approximate molecular weight estimation for small proteins and peptides, with enhanced resolution below 10 kDa.
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Real-Time Visualization: Prestained protein bands allow researchers to monitor electrophoresis progress and confirm protein transfer during Western blotting without additional staining.
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Tri-Color Reference Bands: Distinct green (10 kDa) and red (40 kDa) reference bands make it easy to identify protein migration, orient membranes, and quickly estimate molecular weights.
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Broad Gel Compatibility: Compatible with Tris-Tricine, Tris-Glycine, and Bis-Tris gel systems, allowing the same ladder to be used across multiple electrophoresis protocols.
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Reliable and Reproducible Performance: Protein standards provide consistent band patterns and molecular weight references, helping improve confidence in protein sizing and experimental reproducibility.
Storage/Handling
Store at 4°C for 3 months. Store at -20°C for 24 months.
This product is stable for shipping at ambient temperatures.
