PageRuler™ Unstained High Range Protein Ladder
PageRuler™ Unstained High Range Protein Ladder
Thermo Scientific™

PageRuler™ Unstained High Range Protein Ladder

Thermo Scientific PageRuler Unstained High Range Protein Ladder is a mixture of eight (8) unstained proteins (60 to 250kDa) forRead more
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Catalog NumberQuantity
266372 x 250 μL
Catalog number 26637
Price (CNY)
1,057.00
Each
Add to cart
Quantity:
2 x 250 μL
Request bulk or custom format
Price (CNY)
1,057.00
Each
Add to cart

Thermo Scientific PageRuler Unstained High Range Protein Ladder is a mixture of eight (8) unstained proteins (60 to 250kDa) for use as size standards in protein electrophoresis (SDS-PAGE) and Western blotting.

Features of PageRuler Unstained High Range Protein Ladder:

  • Size range—8 proteins spanning 60 to 250kDa
  • Ready-to-use—supplied in a loading buffer for direct loading on gels
  • Sharp bands—excellent accuracy for detection in with coomassie or silver stains
  • Reference band—150kDa band has greater intensity for easy orientation
  • Tagged—each protein in the ladder contains an integral Strep-tag™ II Sequence
  • Quality tested—each lot evaluated by SDS-PAGE and Western blotting

The protein MW markers in this ladder resolve into clearly identifiable sharp bands when analyzed by SDS-PAGE and stained with coomassie dye or silver. The 150kDa band is of greater intensity and serves as a reference band. Proteins can be detected on Western blots by staining with Ponceau S, coomassie blue or other protein stains. In addition, the ladder proteins contain an integral Step-tag™ II Sequence and may be detected on Western blots using Strep-Tactin™ Conjugates. The PageRuler Unstained High Range Protein Ladder is supplied ready-to-use: no heating, dilution or addition of a reducing agent is required before use.

Includes:

  • Proteins (0.02 to 0.05 mg/mL of each) in 62.5 mM Tris-H3PO4 (pH 7.5 at 25°C), 1 mM EDTA, 2% SDS, 100 mM DTT, 1 mM NaN3, 0.01% bromophenol blue and 33% glycerol

Applications:

  • Accurate protein sizing on SDS-polyacrylamide gels and Western blots.
For Research Use Only. Not for use in diagnostic procedures.
Specifications
For Use With (Application)Tris-acetate gels
Gel CompatibilityBolt™ 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)250, 200, 150, 120, 100, 85, 70, 60 kDa
Product LinePageRuler™
Product TypeProtein Ladder
Quantity2 x 250 μL
Ready to LoadYes
Recommended ApplicationsTris-acetate gels
Shipping ConditionApproved for shipment on Wet or Dry Ice
Stain TypeUnstained
System TypeWestern Blotting, SDS-PAGE
Number of Markers8
Size Range60 to 250 kDa
Unit SizeEach
Contents & Storage
Upon receipt store at -20°C. Product is shipped with an ice pack.

Frequently asked questions (FAQs)

The upper bands of the ladder are missing. What could be the reason?

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.

Find additional tips, troubleshooting help, and resources within our Protein Assays and Analysis Support Center.

Some additional bands or smears were observed on the gel when using a PageRuler unstained ladder. What may have caused this?

Additional bands can appear due to dithiothreitol (DTT) oxidation in the storage buffer. Please add newly prepared DTT solution to the final concentration of 100 mM and boil for 5 min at 95 degrees C. This should solve the issue. Addition of DTT is NOT recommended for prestained protein ladders, since too high a concentration of reducing agents can cause protein destaining.

Find additional tips, troubleshooting help, and resources within our Protein Assays and Analysis Support Center.

Do the proteins in Thermo Scientific protein ladders have a His-Tag or would otherwise react with an anti-His-Tag antibody?

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.

Find additional tips, troubleshooting help, and resources within our Protein Assays and Analysis Support Center.

Can Thermo Scientific protein ladders be detected by Strep-Tactin conjugates?

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.

Find additional tips, troubleshooting help, and resources within our Protein Assays and Analysis Support Center.

Why is non-specific binding detected after Western blot?

Protein ladder bands can sometimes be detected with chemiluminescent techniques due to non-specific interactions of ladder proteins with either primary or secondary antibodies (or with both). The ladder bands are only rarely detected by chromogenic substrates. The extremely high sensitivity of the chemiluminescent assays is needed to see the bands, so the actual degree of cross-reactivity is low. The non-specific cross-reactivity is difficult to predict, it often has a different pattern depending on the antibodies used. If antibodies recognize a linear epitope, the cross-reactivity may be due to sequence homology. If antibodies react with a denaturation-resistant conformational epitope it could be impossible to identify the exact reason for detected cross-reactivity. The most general way to handle this problem would be to use lower concentrations of antibodies.

Find additional tips, troubleshooting help, and resources within our Protein Assays and Analysis Support Center.

View all PageRuler™ Unstained High Range Protein Ladder FAQs