Bolt Bis-Tris Plus Gels

Bolt gels let you see western blot bands more clearly than ever before

Invitrogen Bolt Bis-Tris Plus Gels are optimized gels for western blot analysis. They offer high sample resolution and better sample integrity with easier-to-load, larger capacity wells. 

Bolt Bis-Tris Plus Gels are optimized gels for western blot analysis. Some features include:

  • Superior band quality and band volume—Invitrogen Bolt Bis-Tris Plus chemistry is designed to deliver sharp, straight bands with higher band volume.
  • Better protein resolution—more protein bands are detected due to 10% greater resolving distance and optimized gradient format.
  • Preserved protein integrity—the legendary neutral-pH formulation minimizes protein modifications.
  • Superior lot-to-lot consistency—our best-in-class manufacturing gives you highly reproducible gel performance, with a CV of only 2% for Rf resolution values.
Greater sensitivity with Bolt Bis-Tris Plus gels

Greater sensitivity with Bolt Bis-Tris Plus gels. Total cell extracts from A431 cells were transferred to NC and PVDF membranes from a 4–12% Bolt Bis-Tris Plus gel, and 4–20% Tris-glycine precast gel using the iBlot 2 Gel Transfer Device. The cells were treated with 100 ng/mL of human epidermal growth factor (hEGF) to up-regulate expression of the phospho-EGF receptor. The protein loads of the cell extracts ranged from 20 μg to 1.2 μg of extract. The blots were processed on the iBind Western System using the iBind processing protocols with a 1:200 dilution of Phospho-EGF Receptor (Tyr1068) (1H12) Mouse mAb (Cell Signaling Technology) and a 1:2,000 dilution of anti-mouse HRP secondary antibody (Jackson ImmunoResearch). Detection was performed with Novex ECL HRP Substrate.

More accurate protein molecular weight assignments

Bolt gels are precast SDS-PAGE gels designed to give optimal resolution, band quality, and sensitivity for all your western blot analyses. Bolt gels are 10% longer than competitors’ available gels, which results in higher resolving distance and therefore better band resolution. The pore size of the Bis-Tris Plus chemistry and the well-to-well spacing on Bolt gels offers well-resolved, straight western blot bands with optimal band quality as compared to Bio-Rad’s gels, which may present poorly-resolved, diffuse or streaky bands. Besides providing you with more accurate protein molecular weight assignments, Bolt gels offer overall better-looking, publication-quality western blots.

Preserving the integrity of your proteins

Unlike traditional tris-glycine gels, Bolt Bis-Tris Plus Gels are bis-tris HCl buffered (pH 6.4) and have an operating pH of about 7.0. This neutral pH paired with a unique, gentle sample preparation protocol means your protein samples always reside in mild, nonacidic conditions, preserving the integrity of the proteins and minimizing protein modifications. This helps to ensure highly sensitive, accurate western blot results every time. Bolt gels deliver best-in-class inter-lot and intra-lot reproducibility, with resolution (Rf) CV of only 2%, so you can have increased confidence in your gel performance every day.

Stronger gels

Bolt gels have been shown to be less fragile than Bio-Rad’s gels. The western workflow requires significant gel handling, so we developed Bolt gels to be stronger than other commercially available gels in order to minimize gel tearing.

More sample per well

Our unique, innovative wedge-shaped wells enable up to two times the protein sample loads, so you get easy sample loading and no more spillover.


Bolt gels are designed for speed without a compromise in quality. With our 7-minute Invitrogen iBlot 2 western blot transfer process, now you can be western-ready in as little as 42 minutes without sacrificing quality.

Bolt WedgeWell

The unique wedge-shaped well in every Bolt gel provides higher loading capacity, so you can load up to twice as much protein sample in every well. 

Well size Recommended loading volume Maximum loading volume Maximum protein load
10-well 40 µL 60 µL 0.5 µg/band
12-well 30 µL 45 µL 0.4 µg/band
15-well 20 µL 35 µL 0.25 µg/band
17-well 15 µL 30 µL 0.2 µg/band

Detect proteins even in dilute samples or measure expression of low-abundance proteins. With more room to load your sample, you no longer have to worry about sample spillover and cross-well contamination on your western blots. Gel loading is also easier with no need to use special gel-loading pipette tips.

High sample volume capacity of Bolt WedgeWell gels
High sample volume capacity of Bolt WedgeWell gels. (A) Increasing volumes (40–70μL) of a fluorescent protein standard were loaded in every other lane of an Invitrogen Bolt 4–12% Bis-Tris Plus 10-well Gel. (B) Increasing volumes (10–40 μL) of the same protein standard were loaded in every other lane of Bio-Rad's 4–20% 10-well gel. Sample spillover and cross-well contamination is observed as signals from the sample loaded in the adjacent wells.

Bolt band quality

Bolt Bis-Tris Plus Gels are designed to deliver well-resolved, straight bands with optimal band quality as compared to other commercially available precast gels.

Western blot band quality with Bolt precast gels

Western blot band quality with Bolt precast gels. GST fusion proteins were loaded at 20-µL sample volume. Sharp, straight western bands are observed with Bolt Bis-Tris gradient gels (A) as compared to smeared, poorly resolved, and uneven western signals on Bio-Rad’s tris-glycine gradient gels (B). Western detection was performed for (A) and (B) with Invitrogen WesternBreeze chemiluminescent detection using a mouse anti-GST monoclonal antibody at 1:1,000 dilution; an LAS-1000 (FujiFilm) imager was used with an exposure time of 40 seconds. Chromogenic detection was performed for gels (C) and (D). Lane 1: blend of 6 purified proteins; lanes 2–4, 6–7: 250 ng of various GST fusion proteins; lane 5: mix of GST fusion proteins from lanes 4 and 6; lane 8: p53-GST; lane 9: GST; lane 10: Invitrogen MagicMark XP Western Protein Standard. 

Bolt band integrity

Bolt gels preserve protein integrity with neutral-pH gel chemistry. This formulation minimizes protein modifications during electrophoresis. 

A western blot of a Bolt gel shows clean, sharp protein signals corresponding to only full-length proteins, whereas a western blot of a Bio-Rad TGX gel shows multiple low molecular weight degradation products
A western blot of a Bolt gel shows clean, sharp protein signals corresponding to only full-length proteins, whereas a western blot of a Bio-Rad TGX gel shows multiple low molecular weight degradation products. Protein kinases implicated in cancer (IKKϐ, EPHB3, HCK, MAPK14, FLT1 and DDR2) were analyzed on a Bolt Bis-Tris Plus Gel and a Bio-Rad TGX tris-glycine gel. The purified kinases (50 ng each), along with MagicMark protein standard and purified recombinant GST protein, were loaded on a 10-well, 4–12% Bolt gel and a 10-well, 4–20% Bio-Rad TGX gel. The samples were separated and transferred to 0.45-μm PVDF membranes using the respective manufacturers’ protocols. Immunodetection was performed using an anti-GST antibody and WesternBreeze chemiluminescence detection.

Bolt band resolution

Bolt Bis-Tris Plus Gels have better resolving power than Bio-Rad’s gels. With 10% greater resolving distance, optimized gel chemistry, and gradient format, you can see more protein bands resolved on a Bolt gel compared to other commercially available precast gels. In experimental analysis, you can see two separate bands for the insulin B chain and insulin A chain, which have similar molecular weights. The protein bands on the Bolt gel appear straight and the signal intensities are even across the entire bands, whereas the protein bands on Bio-Rad’s gel are uneven and of poor quality.

Bolt Bis-Tris Gel band resolution—comparison of Bio-Rad's stained protein gels

Bolt Bis-Tris Gel band resolution—comparison of Bio-Rad's stained protein gels. (A) Bolt Bis-Tris gradient gel stained with Invitrogen SimplyBlue SafeStain. (B) Bio-Rad's tris-glycine gradient gel stained with competitor’s stain. (C) Enlargement of a section of lane 5 from the two gels shows the insulin B chain (3.5 kDa) and insulin A chain (2.5 kDa). The resolution of the two bands is superior on the Bolt gel.

The Bolt Bis-Tris Plus chemistry and optimized well dimensions are designed to deliver well-to-well reproducibility and band volume correspondence to sample load, therefore providing better quantitation capabilities on western blots as compared to westerns of Bio-Rad’s gels. Western blots of dilution series of GST fusion proteins loaded on Bolt gels show even, stepwise gradations, whereas Bio-Rad’s gels show less even gradation of the same dilution series. In addition, the overall western signal detected on the blot of the Bolt gel, as defined by band volume, is higher than on the blot of Bio-Rad’s gel.

Western blot band volumes on Bolt gels vs. Bio-Rad TGX gels
Western blot band volumes on Bolt gels vs. Bio-Rad TGX gels. (A) Blot of a Bolt 4–12% gel. (B) Blot of a Bio-Rad TGX™ 4–20% gel. Two GST fusion proteins as well as GST were spiked into E. coli lysate (0.6 mg per gel lane) to create a series of decreasing, increasing, or constant amounts of these proteins across the gel. The spiked amounts of the two fusion proteins ranged from 40 ng to 0.2 ng per gel lane. Electrophoresis and wet transfers to PVDF membranes were performed using the materials, methods, equipment, and instructions of each manufacturer. Invitrogen WesternBreeze Chemiluminescent Kits were used with an anti-GST antibody; images were acquired with an LAS-1000 (FujiFilm) system. (C) Band volumes measured on western blots of Bolt and Bio-Rad TGX gels. Eight wells on each gel were loaded with 2 ng of GST. Band volumes were calculated based on the width, length and intensity of the detected band. 
Bolt Bis-Tris Plus migration chart