NuPAGE Bis-Tris Precast Gels

Invitrogen NuPAGE Bis-Tris Gels are high-performance gels that offer optimized chemistry for high sensitivity applications.

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NuPAGE Bis-Tris Gel specifications

Available gel sizes Mini: 8 cm x 8 cm (1 or 1.5 mm thick)
Midi: 8 cm x 13 cm (1 mm thick)
Storage conditions Room temperature
Shelf life 12 months
Recommended sample buffer NuPAGE LDS Sample Buffer
Recommended running buffers NuPAGE MES SDS or NuPAGE MOPS SDS Running Buffer
Recommended transfer buffer NuPAGE Transfer Buffer
Gel chemistry Bis-Tris
Available polyacrylamide concentrations 8%, 10%, 12%, 4–12%
Separation range 1.5–300 kDa
For use with (equipment) mini gels Mini Gel Tank or XCell SureLock Mini-Cell
For use with (equipment) midi gels Invitrogen XCell4 SureLock Midi-Cell or Bio-Rad Criterion (with adapters only)
Mode of separation Molecular weight
Application SDS-PAGE
Available Wells configurations* Mini: 1, 9, 10, 12, 15, 17, 2D-well, IPG well
Midi: 12+2, 20, 26 wells

*Not all percentages are available in every well type

Sharp, straight bands

Neutral-pH buffers in NuPAGE Bis-Tris Gels deliver sharp straight bands. During separation, NuPAGE Bis-Tris Gels operate close to pH 7. In the Laemmli system, the gel is run at basic pH (pH ~9.5). At high pH the residual unpolymerized acrylamide can react with cysteine and lysine residues of the proteins being separated. This may affect downstream analysis such as western blot transfer. At the neutral pH of NuPAGE Bis-Tris Gels, these reactions take place several orders of magnitude more slowly than at the basic pH of tris-glycine gels, resulting in sharper bands and better resolution.

NuPAGE Bis-Tris gels provide sharp straight bands compared to competitor tris glycine gels

Protein separation comparing NuPAGE Bis-Tris Gel and traditional tris-glycine gel. The samples listed below were run on (A) a NuPAGE 4–12% Bis-Tris Gel in Invitrogen NuPAGE MES SDS Running Buffer or (B) another manufacturer’s 4–20% tris-glycine gel. Note the high resolution of the sample bands in the NuPAGE protein gel. The poorly resolved “fuzzy” bands seen in the other manufacturer’s gel are a result of reoxidation of some disulfide bonds within the sample, leading to slight changes in migration rates. Lanes 1, 6, 7, 10: Invitrogen Mark12 Unstained Standard; lane 2: high protein load (4 proteins, 6 µg/protein); lane 3: Broad Range Standard; lanes 4, 5: E. coli extract; lane 8: E-PAGE SeeBlue Pre-stained Standard; lane 9: Invitrogen MultiMark Multi-Colored Protein Standard.

Better sample integrity

Sample preparation is a crucial step in successful protein analysis. The pH of the traditional Laemmli-style sample buffer changes from 6.8 to 5.2 when heated at 100°C. This lower pH is known to induce aspartyl-prolyl (Asp-Pro) peptide bond cleavage, which leads to protein degradation. By maintaining a >7.0 pH environment, the Invitrogen NuPAGE LDS Sample Buffer preserves protein integrity by minimizing this Asp-Pro cleavage. As seen below, the sample integrity is maintained throughout electrophoresis with the Invitrogen NuPAGE system; protein degradation is seen in samples prepared with Laemmli (tris-glycine) sample buffer. The Invitrogen NuPAGE Antioxidant running buffer additive greatly minimizes protein oxidation during electrophoresis and keeps reduced protein bands sharp and clear.

NuPAGE gel system provides better sample integrity than the traditional Laemmli (tris-glycine) gel system

High sample integrity. Integrity of samples is maintained throughout electrophoresis with the NuPAGE Bis-Tris Gel System (left), compared to samples prepared with Laemmli (tris-glycine) sample buffer (right).

NuPAGE Bis-Tris Gels are precast polyacrylamide gels designed to give optimal separation for a wide range of molecular weight proteins during gel electrophoresis. NuPAGE Bis-Tris Gels have a neutral pH environment that minimizes protein modifications, resulting in sharper bands without typical gel "smiling.” NuPAGE Bis-Tris Gels can be used for western blotting, sequencing, mass spectrometry, and any other application in which protein integrity is crucial.

Features of the NuPAGE Bis-Tris Gels include:

  • Better protein integrity—optimized sample preparation process preserves your proteins
  • Wide ranges of molecular weight separation—selecting the right gel and running buffer helps to achieve the optimal separation of your proteins
  • Faster run times—separation of your proteins can be attained in as little as 35 minutes
  • Longer shelf life— gels can be stored for at least 12 months at room temperature

NuPAGE Bis-Tris Gels are formulated for denaturing gel electrophoresis applications. For optimal sample preparation, we recommend using buffers containing SDS. The gels can be run using MES SDS running buffer to better resolve small proteins and MOPS SDS running buffer to resolve medium- to large-size proteins. 

NuPAGE Bis-Tris Gels use a bis-tris discontinuous buffer system involving three ions:

  • Chloride (–) is from the gel buffer and serves as a leading ion due to its high affinity to the anode relative to other anions in the system. The gel buffer ions are bis-tris (+) and Cl (–) (pH 6.4).
  • MES or MOPS (–) serves as the trailing ion in the running buffer. The running buffer ions are tris (+), MOPS/MES (–) and dodecylsuflate (pH 7.3–7.7).

Bis-tris (+) is the common ion present in the gel buffer and running buffer. The combination of lower pH gel buffer (pH 6.4) and the running buffer (pH 7.3–7.7) results in a significantly lower operating pH of 7 during electrophoresis. 

Currently using Tris-glycine or Tricine gels? Use the NuPAGE Gel conversion guide below to find the appropriate NuPAGE gel and corresponding optimized buffer. 

NuPAGE Gel conversion guide

If you are using: Then we recommend NuPAGE gel: Buffer system
Tris-Glycine gel
4% NuPAGE 3-8% Tris-Acetate Tris-Acetate
6% NuPAGE 3-8% Tris-Acetate Tris-Acetate
10% NuPAGE 8% Bis-Tris MOPS
NuPAGE 10% Bis-Tris MOPS
12% NuPAGE 10% Bis-Tris MOPS
14% NuPAGE 12% Bis-Tris MOPS
16% NuPAGE 12% Bis-Tris MES
18% NuPAGE 12% Bis-Tris MES
4-12% NuPAGE 3-8% Tris-Acetate Tris-Acetate
NuPAGE 4-12% Bis-Tris MOPS
4-20% NuPAGE 4-12% Bis-Tris MES
8-16% NuPAGE 4-12% Bis-Tris MOPS
10-20% NuPAGE 12% Bis-Tris MOPS
Tricine gel
10% NuPAGE 8% Bis-Tris MES
NuPAGE 10% Bis-Tris MES
16% NuPAGE 4-12% Bis-Tris MES
10-20% NuPAGE 4-12% Bis-Tris MES
Migration chart for NuPAGE Bis-Tris Gels

NuPAGE Bis-Tris Gel specifications

Available gel sizes Mini: 8 cm x 8 cm (1 or 1.5 mm thick)
Midi: 8 cm x 13 cm (1 mm thick)
Storage conditions Room temperature
Shelf life 12 months
Recommended sample buffer NuPAGE LDS Sample Buffer
Recommended running buffers NuPAGE MES SDS or NuPAGE MOPS SDS Running Buffer
Recommended transfer buffer NuPAGE Transfer Buffer
Gel chemistry Bis-Tris
Available polyacrylamide concentrations 8%, 10%, 12%, 4–12%
Separation range 1.5–300 kDa
For use with (equipment) mini gels Mini Gel Tank or XCell SureLock Mini-Cell
For use with (equipment) midi gels Invitrogen XCell4 SureLock Midi-Cell or Bio-Rad Criterion (with adapters only)
Mode of separation Molecular weight
Application SDS-PAGE
Available Wells configurations* Mini: 1, 9, 10, 12, 15, 17, 2D-well, IPG well
Midi: 12+2, 20, 26 wells

*Not all percentages are available in every well type

Sharp, straight bands

Neutral-pH buffers in NuPAGE Bis-Tris Gels deliver sharp straight bands. During separation, NuPAGE Bis-Tris Gels operate close to pH 7. In the Laemmli system, the gel is run at basic pH (pH ~9.5). At high pH the residual unpolymerized acrylamide can react with cysteine and lysine residues of the proteins being separated. This may affect downstream analysis such as western blot transfer. At the neutral pH of NuPAGE Bis-Tris Gels, these reactions take place several orders of magnitude more slowly than at the basic pH of tris-glycine gels, resulting in sharper bands and better resolution.

NuPAGE Bis-Tris gels provide sharp straight bands compared to competitor tris glycine gels

Protein separation comparing NuPAGE Bis-Tris Gel and traditional tris-glycine gel. The samples listed below were run on (A) a NuPAGE 4–12% Bis-Tris Gel in Invitrogen NuPAGE MES SDS Running Buffer or (B) another manufacturer’s 4–20% tris-glycine gel. Note the high resolution of the sample bands in the NuPAGE protein gel. The poorly resolved “fuzzy” bands seen in the other manufacturer’s gel are a result of reoxidation of some disulfide bonds within the sample, leading to slight changes in migration rates. Lanes 1, 6, 7, 10: Invitrogen Mark12 Unstained Standard; lane 2: high protein load (4 proteins, 6 µg/protein); lane 3: Broad Range Standard; lanes 4, 5: E. coli extract; lane 8: E-PAGE SeeBlue Pre-stained Standard; lane 9: Invitrogen MultiMark Multi-Colored Protein Standard.

Better sample integrity

Sample preparation is a crucial step in successful protein analysis. The pH of the traditional Laemmli-style sample buffer changes from 6.8 to 5.2 when heated at 100°C. This lower pH is known to induce aspartyl-prolyl (Asp-Pro) peptide bond cleavage, which leads to protein degradation. By maintaining a >7.0 pH environment, the Invitrogen NuPAGE LDS Sample Buffer preserves protein integrity by minimizing this Asp-Pro cleavage. As seen below, the sample integrity is maintained throughout electrophoresis with the Invitrogen NuPAGE system; protein degradation is seen in samples prepared with Laemmli (tris-glycine) sample buffer. The Invitrogen NuPAGE Antioxidant running buffer additive greatly minimizes protein oxidation during electrophoresis and keeps reduced protein bands sharp and clear.

NuPAGE gel system provides better sample integrity than the traditional Laemmli (tris-glycine) gel system

High sample integrity. Integrity of samples is maintained throughout electrophoresis with the NuPAGE Bis-Tris Gel System (left), compared to samples prepared with Laemmli (tris-glycine) sample buffer (right).

NuPAGE Bis-Tris Gels are precast polyacrylamide gels designed to give optimal separation for a wide range of molecular weight proteins during gel electrophoresis. NuPAGE Bis-Tris Gels have a neutral pH environment that minimizes protein modifications, resulting in sharper bands without typical gel "smiling.” NuPAGE Bis-Tris Gels can be used for western blotting, sequencing, mass spectrometry, and any other application in which protein integrity is crucial.

Features of the NuPAGE Bis-Tris Gels include:

  • Better protein integrity—optimized sample preparation process preserves your proteins
  • Wide ranges of molecular weight separation—selecting the right gel and running buffer helps to achieve the optimal separation of your proteins
  • Faster run times—separation of your proteins can be attained in as little as 35 minutes
  • Longer shelf life— gels can be stored for at least 12 months at room temperature

NuPAGE Bis-Tris Gels are formulated for denaturing gel electrophoresis applications. For optimal sample preparation, we recommend using buffers containing SDS. The gels can be run using MES SDS running buffer to better resolve small proteins and MOPS SDS running buffer to resolve medium- to large-size proteins. 

NuPAGE Bis-Tris Gels use a bis-tris discontinuous buffer system involving three ions:

  • Chloride (–) is from the gel buffer and serves as a leading ion due to its high affinity to the anode relative to other anions in the system. The gel buffer ions are bis-tris (+) and Cl (–) (pH 6.4).
  • MES or MOPS (–) serves as the trailing ion in the running buffer. The running buffer ions are tris (+), MOPS/MES (–) and dodecylsuflate (pH 7.3–7.7).

Bis-tris (+) is the common ion present in the gel buffer and running buffer. The combination of lower pH gel buffer (pH 6.4) and the running buffer (pH 7.3–7.7) results in a significantly lower operating pH of 7 during electrophoresis. 

Currently using Tris-glycine or Tricine gels? Use the NuPAGE Gel conversion guide below to find the appropriate NuPAGE gel and corresponding optimized buffer. 

NuPAGE Gel conversion guide

If you are using: Then we recommend NuPAGE gel: Buffer system
Tris-Glycine gel
4% NuPAGE 3-8% Tris-Acetate Tris-Acetate
6% NuPAGE 3-8% Tris-Acetate Tris-Acetate
10% NuPAGE 8% Bis-Tris MOPS
NuPAGE 10% Bis-Tris MOPS
12% NuPAGE 10% Bis-Tris MOPS
14% NuPAGE 12% Bis-Tris MOPS
16% NuPAGE 12% Bis-Tris MES
18% NuPAGE 12% Bis-Tris MES
4-12% NuPAGE 3-8% Tris-Acetate Tris-Acetate
NuPAGE 4-12% Bis-Tris MOPS
4-20% NuPAGE 4-12% Bis-Tris MES
8-16% NuPAGE 4-12% Bis-Tris MOPS
10-20% NuPAGE 12% Bis-Tris MOPS
Tricine gel
10% NuPAGE 8% Bis-Tris MES
NuPAGE 10% Bis-Tris MES
16% NuPAGE 4-12% Bis-Tris MES
10-20% NuPAGE 4-12% Bis-Tris MES
Migration chart for NuPAGE Bis-Tris Gels
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