Gel Running Buffers

Q: Which of the three products do I need?

Follow the gel. Polyacrylamide protein work, denaturing or native, takes Protein Running Buffers (Tris-Glycine-SDS or Tris-Glycine). Horizontal DNA or RNA runs take DNA/RNA Running Buffers in a TAE or TBE formulation. Denaturing RNA gels take MOPS Running Buffer [10X]. The three cover different separation problems rather than different quality tiers.

Q: Should I use TAE or TBE?

It depends on fragment size and on what happens to the DNA afterwards. TAE gives better resolution and recovery of large fragments above roughly 4 kb, and acetate is friendlier to downstream enzymatic steps such as ligation and digestion - but its weak buffering capacity exhausts on long or high-voltage runs. TBE has stronger, longer-lasting buffering capacity, gives sharper resolution of small fragments below roughly 1 to 2 kb, and tolerates long runs well - but borate can inhibit some downstream enzymes and complicates gel extraction.

Q: Why is Tris-Glycine specifically the standard for protein gels?

Because in the Laemmli discontinuous system the buffer is not a passive conductor. The pH-dependent mobility of glycine relative to chloride is what stacks proteins into a razor-thin band before they enter the resolving gel. That stacking is the reason the bands are sharp, and it is why substituting a generic conductive salt does not give the same result. It has been the default chemistry for essentially all denaturing protein electrophoresis since 1970.

Q: Why does the SDS-PAGE running buffer contain SDS if the sample buffer already did?

Because SDS strips off migrating proteins in transit. The running buffer continuously replenishes it, keeping the proteins uniformly coated and unfolded for the whole separation rather than only at the moment of loading. Without that replenishment the uniform charge-to-mass ratio that makes migration track molecular weight would degrade as the run went on.

Q: Why MOPS for RNA gels rather than a Tris-based buffer?

Because of where it buffers. MOPS has a pKa near neutral, around 7.2, with a buffering range of 6.5 to 7.9. That holds pH stable across a long run and prevents the alkaline-driven degradation that single-stranded RNA is vulnerable to. MOPS-based buffers were adopted for denaturing RNA gels in the 1970s and 1980s specifically to protect fragile single-stranded transcripts.

Q: My gel is overheating and the bands are distorted. Is the buffer the problem?

It can be. Conductivity and heat generation rise together, so a higher-conductivity buffer at a given voltage produces more Joule heating - enough to melt agarose or to smudge and distort polyacrylamide bands. Lower-resistance, correctly formulated buffers let gels run at higher voltages without that excess heat, which is why lower-ionic-strength media were developed to allow faster, cooler runs. Check the buffer formulation and concentration before assuming the problem is the power supply.

Q: How long does a tank of running buffer last?

Buffering capacity is finite, and the two nucleic-acid chemistries differ sharply here. TAE's weak buffering capacity exhausts on long or high-voltage runs, so it is best suited to shorter runs or to setups with buffer recirculation. TBE's stronger, longer-lasting capacity tolerates long runs well. This is one of the main practical reasons to choose between them.

Product#: Buffers-Gel-Running-Buffers

$0.00

Select Buffers-Group

see below the table

Availability:

Ships in 24 hours

Description
Reviews (0)

warning For Research Use Only (RUO). Not intended for clinical, diagnostic, or therapeutic use in humans.

bolt Tris-Glycine · TAE / TBE · MOPS Running-Buffer Chemistries

Gel Running Buffers

This is a category page, not a product page — pick the buffer chemistry that matches your gel and click View to open that product page. The chemistry reference, applications, and FAQ follow below.

Gel Running Buffers — Catalog · 3 Products

Select the buffer that matches your separation — click View for the product page.

Product	Core Attributes	Best Use	Product Page
Protein Running Buffers	Tris-Glycine-SDS (denaturing) or Tris-Glycine (native)	Core protein standard — maintains uniform negative charge and stable migration to resolve complex lysates on polyacrylamide. Tricine variants outperform glycine for small peptides (<20 kDa).	Viewarrow_forward
DNA/RNA Running Buffers	TAE or TBE formulations	Core genomics standard — clean conductivity and tight band definition for horizontal DNA/RNA runs. The choice between TAE and TBE depends on fragment size and downstream use (see the bench note below).	Viewarrow_forward
MOPS Running Buffer [10X]	Concentrated 3-(N-morpholino)propanesulfonic acid	Gold standard for denaturing RNA gels — pKa near neutral (~7.2, buffering range 6.5–7.9) holds pH stable and prevents alkaline-driven degradation of single-stranded RNA over long runs.	Viewarrow_forward

Not sure which chemistry? Compare the buffer systems · See applications by workflow · Read the FAQ

Category Snapshot

What a running buffer actually does

Once a gel is cast and loaded, electromigration needs a complete electrical circuit. Gel running buffers (electrophoresis buffers) are the conductive solutions that fill the tank and submerge the gel. They do two jobs at once: supply the ions that carry current between the electrodes and maintain a stable pH that protects both the gel matrix and the migrating macromolecules throughout the run.

Three products, three separation problems. Protein Running Buffers for polyacrylamide protein work, DNA/RNA Running Buffers for horizontal nucleic acid runs, MOPS Running Buffer [10X] for denaturing RNA gels.
Not a passive conductor. In the Laemmli system the pH-dependent mobility of glycine relative to chloride is what stacks proteins into a razor-thin band before they enter the resolving gel.
TAE and TBE are a genuine trade-off, not a preference. Resolution and downstream compatibility pull in opposite directions — the bench note below sets out both sides.
MOPS buffers near neutral. A pKa around 7.2 with a buffering range of 6.5–7.9 holds pH steady across long runs and prevents alkaline-driven degradation of single-stranded RNA.
Conductivity and heat rise together. Lower-ionic-strength media allow faster, cooler runs at higher voltage without melting agarose or distorting polyacrylamide bands.
SDS-PAGE running buffer keeps working during the run. It continuously replenishes the SDS that strips off migrating proteins in transit, keeping them uniformly coated and unfolded.

Tris-Glycine TAE / TBE RUO

CATEGORY REFERENCE · GEL RUNNING BUFFERS

The category at a glance — chemistries, the figures that decide a choice, and what each one is for

Products in this category3
Buffer systems coveredTris-Glycine, Tris-Glycine-SDS, Tricine, TAE, TBE, MOPS
MOPS pK_a~7.2
MOPS buffering rangepH 6.5–7.9
TAE favours fragments>~4 kb
TBE favours fragments<~1–2 kb
Tricine over glycine below~20 kDa^[b]
MOPS concentration supplied10X
Tris-dominant era in DNA work~3 decades (1970s–2000s)
Intended useResearch Use Only (RUO)

[b] The ~20 kDa figure is the source's own. The controlling published protocol (Schägger 2006) describes Tricine–SDS-PAGE as the preferred system below 30 kDa. The two differ in scope rather than in fact, so the source value is reproduced unchanged — see the note under the chemistry table.

Why Gel Running Buffers Are Needed

Six things the tank buffer is doing while your gel runs

A running buffer is the only reagent in an electrophoresis run that is working continuously from the first volt to the last. Each card below is one of the jobs it is doing in that time.

bolt

Electrical conductivity

Pure water conducts too poorly to drive molecules through a matrix. Running buffers supply the mobile ions — Tris⁺, glycine, borate, acetate, Na⁺, Cl⁻ — that carry current from cathode to anode.

science

pH control against electrolysis

Passing current through water generates acid (H⁺) at the anode and base (OH⁻) at the cathode. Unbuffered, that shift would flip the charge state of the macromolecules and break down the gel. The buffer absorbs it.

thermostat

Joule heating management

Lower-resistance, correctly formulated buffers let gels run at higher voltages without the excess heat that melts agarose or smudges and distorts polyacrylamide bands. Conductivity and heat generation rise together, which is why low-ionic-strength media allow faster runs.

layers

Denaturing-environment integrity

In runs like SDS-PAGE the running buffer continuously replenishes the SDS that strips off migrating proteins in transit, keeping them uniformly coated and unfolded for the whole separation.

battery_alert

Buffering capacity has a lifetime

Capacity is finite. TAE's weak buffering capacity exhausts on long or high-voltage runs, which is why it suits shorter runs or runs with buffer recirculation. TBE's stronger, longer-lasting capacity tolerates long runs well.

link

What happens after the gel

The buffer follows the DNA into the next step. Acetate is friendlier to downstream enzymatic work such as ligation and digestion; borate can inhibit some downstream enzymes and complicates gel extraction, so it is less ideal when the DNA will be recovered for cloning.

The decision this category really turns on

For nucleic acids, it is TAE versus TBE — and the answer depends on two questions, not one. First, how big is the fragment: TAE gives better resolution and recovery above roughly 4 kb, TBE gives sharper resolution below roughly 1–2 kb. Second, what happens to the DNA next: if you are cutting a band out and cloning it, acetate is the friendlier ion. If you are running long and just need clean, stable separation, borate holds up better. Pick for the run you are actually doing.

~7.2

MOPS pK_a — near-neutral, buffering across pH 6.5 to 7.9

4 kb

above this, TAE resolves and recovers better; below ~1–2 kb, TBE is sharper

History & Standardization

How running buffers became specific chemistries rather than salt water

Four developments, each of which explains a buffer still sitting on the shelf today. The eras and their significance are reproduced from the source.

1

1950s–1960s Early zone electrophoresis

Early zone electrophoresis relied on simple saline solutions, which conducted unevenly, overheated, and gave diffuse bands as polyacrylamide and agarose replaced starch and paper matrices. Significance: it showed that generic salt solutions were inadequate — weak organic acids and bases were needed to carry current smoothly without cooking the gel.
2

1970 Tris-Glycine becomes the protein standard

Laemmli's discontinuous SDS-PAGE system made Tris-Glycine the standard protein running buffer.^[1] Here the buffer is not a passive conductor: the pH-dependent mobility of glycine relative to chloride is what stacks proteins into a razor-thin band before they enter the resolving gel. Significance: it became the default running-buffer chemistry for essentially all denaturing protein electrophoresis, and remains so today.
3

1970s–1980s TAE, TBE, and MOPS

TAE (Tris-Acetate-EDTA) and TBE (Tris-Borate-EDTA) became the worldwide standards for nucleic acids, each trading resolution against buffering capacity differently. MOPS-based buffers were adopted for denaturing RNA gels to protect fragile single-stranded transcripts.^[3] Significance: this established the modern toolkit of running buffers matched to specific separation goals.
4

~1970s–2000s Three decades of Tris, then cooler alternatives

DNA electrophoresis conductive media stayed remarkably stable for roughly three decades, with Tris as the dominant cation — a continuity documented in Brody & Kern's 2004 review.^[2] Significance: it confirmed how well the early Tris-based systems worked, while later low-conductivity media (for example lithium or sodium borate) emerged to enable faster, cooler runs.

Buffer Chemistry Reference

The six chemistries behind the three products

Each product on this page covers more than one buffer system. This table breaks them out so you can match a chemistry to a gel before you choose a product.

Buffer system	Ions that do the work	What it contributes to the run	Typical separation	Product on this page
Tris-Glycine (native)	Tris⁺, glycine, chloride	The pH-dependent mobility of glycine relative to chloride stacks proteins into a razor-thin band before they enter the resolving gel	Native-PAGE — intact complexes and enzyme activity	Protein Running Buffers
Tris-Glycine-SDS (denaturing)	Tris⁺, glycine, chloride, SDS	Adds the stacking effect above to a continuous replenishment of the SDS that strips off migrating proteins in transit, keeping them uniformly coated and unfolded	SDS-PAGE — denatured protein subunits	Protein Running Buffers
Tris-Tricine	Tris⁺, tricine in place of glycine	Outperforms glycine for small peptides (<20 kDa)^[b]	SDS-PAGE of small peptides	Protein Running Buffers — named by the source as a variant
TAE (Tris-Acetate-EDTA)	Tris⁺, acetate, EDTA	Better resolution and recovery of large fragments; acetate is friendlier to downstream enzymatic steps. Weak buffering capacity exhausts on long or high-voltage runs	Horizontal DNA/RNA runs, fragments >~4 kb	DNA/RNA Running Buffers
TBE (Tris-Borate-EDTA)	Tris⁺, borate, EDTA	Stronger, longer-lasting buffering capacity and sharper resolution of small fragments; borate can inhibit some downstream enzymes and complicates gel extraction	Horizontal DNA/RNA runs, fragments <~1–2 kb	DNA/RNA Running Buffers
MOPS	3-(N-morpholino)propanesulfonic acid	pK_a near neutral (~7.2, buffering range 6.5–7.9) holds pH stable and prevents alkaline-driven degradation of single-stranded RNA over long runs	Denaturing RNA gels — structural RNA profiling, Northern blot prep	MOPS Running Buffer [10X]

On the Tricine threshold. The source gives <20 kDa as the point below which Tricine outperforms glycine. That figure was checked against the controlling published protocol, which describes Tricine–SDS-PAGE as covering 1–100 kDa and as the preferred system for resolving proteins smaller than 30 kDa.^[4] The two numbers describe different things — where Tricine becomes clearly better versus where it becomes the recommended default — so the source value has been reproduced unchanged rather than corrected. If your peptides sit between 20 and 30 kDa, consult the published protocol before assuming glycine is adequate. This clarification is an addition beyond the source description.

Applications

Where each buffer chemistry is used

One tab per application named in the source. Product assignments appear only where the source itself makes them — where it does not, the tab says so rather than guessing.

DNA/RNA Running Buffers · TAE or TBE

PCR products
Plasmids
Restriction digests
Genomic DNA

Protein Running Buffers · Tris-Glycine-SDS or Tris-Glycine

Denatured protein subunits, on vertical SDS-PAGE
Intact complexes and enzyme activity, on vertical Native-PAGE
Complex lysates resolved on polyacrylamide, with uniform negative charge and stable migration
Small peptides (<20 kDa), where Tricine variants outperform glycine^[b]

MOPS Running Buffer [10X] · formaldehyde / MOPS gels

Structural RNA profiling
Northern blot preparation
Long runs where pH stability protects fragile single-stranded transcripts from alkaline-driven degradation

DNA/RNA Running Buffers · TAE or TBE

DNA fragment sizing
Restriction mapping
Routine cloning workflows
Diagnostic workflows

Product assignment not stated in source

Isoelectric focusing
2D electrophoresis — supporting the resolving dimension after first-dimension separation
The source lists this application for the category but does not assign it to a specific product. Contact support@diagnocine.com to confirm which buffer suits your second-dimension protocol.

Bench Note — Choosing a Nucleic-Acid Buffer

TAE or TBE

Both ship under DNA/RNA Running Buffers, and neither is simply better. This table sets the source's bench note out side by side.

	TAE (Tris-Acetate-EDTA)	TBE (Tris-Borate-EDTA)
Resolution and recovery of large fragments	check_circle Better, above ~4 kb	Less suited to large fragments
Resolution of small fragments	Less sharp	check_circle Sharper, below ~1–2 kb
Buffering capacity	Weak — exhausts on long or high-voltage runs	check_circle Stronger and longer-lasting
Long runs	Best for shorter runs, or with buffer recirculation	check_circle Tolerates long runs well
Downstream enzymatic steps (ligation, digestion)	check_circle Acetate is friendlier	cancel Borate can inhibit some enzymes
Recovering DNA from the gel for cloning	check_circle Preferred	cancel Borate complicates gel extraction

Shared across the category. For Research Use Only (RUO) — not intended for clinical, diagnostic, or therapeutic use in humans.

FAQ

Frequently asked questions

The questions that come up most often when a bench protocol meets a purchase order.

Follow the gel. Polyacrylamide protein work, denaturing or native, takes Protein Running Buffers (Tris-Glycine-SDS or Tris-Glycine). Horizontal DNA or RNA runs take DNA/RNA Running Buffers in a TAE or TBE formulation. Denaturing RNA gels take MOPS Running Buffer [10X]. The three cover different separation problems rather than different quality tiers.

It depends on fragment size and on what happens to the DNA afterwards. TAE gives better resolution and recovery of large fragments above roughly 4 kb, and acetate is friendlier to downstream enzymatic steps such as ligation and digestion — but its weak buffering capacity exhausts on long or high-voltage runs. TBE has stronger, longer-lasting buffering capacity, gives sharper resolution of small fragments below roughly 1 to 2 kb, and tolerates long runs well — but borate can inhibit some downstream enzymes and complicates gel extraction.

Because in the Laemmli discontinuous system the buffer is not a passive conductor. The pH-dependent mobility of glycine relative to chloride is what stacks proteins into a razor-thin band before they enter the resolving gel. That stacking is the reason the bands are sharp, and it is why substituting a generic conductive salt does not give the same result. It has been the default chemistry for essentially all denaturing protein electrophoresis since 1970.

Because SDS strips off migrating proteins in transit. The running buffer continuously replenishes it, keeping the proteins uniformly coated and unfolded for the whole separation rather than only at the moment of loading. Without that replenishment the uniform charge-to-mass ratio that makes migration track molecular weight would degrade as the run went on.

Because of where it buffers. MOPS has a pKa near neutral, around 7.2, with a buffering range of 6.5 to 7.9. That holds pH stable across a long run and prevents the alkaline-driven degradation that single-stranded RNA is vulnerable to. MOPS-based buffers were adopted for denaturing RNA gels in the 1970s and 1980s specifically to protect fragile single-stranded transcripts.

It can be. Conductivity and heat generation rise together, so a higher-conductivity buffer at a given voltage produces more Joule heating — enough to melt agarose or to smudge and distort polyacrylamide bands. Lower-resistance, correctly formulated buffers let gels run at higher voltages without that excess heat, which is why lower-ionic-strength media were developed to allow faster, cooler runs. Check the buffer formulation and concentration before assuming the problem is the power supply.

Buffering capacity is finite, and the two nucleic-acid chemistries differ sharply here. TAE's weak buffering capacity exhausts on long or high-voltage runs, so it is best suited to shorter runs or to setups with buffer recirculation. TBE's stronger, longer-lasting capacity tolerates long runs well. This is one of the main practical reasons to choose between them.

Key References

The source's reference list

Reproduced from the source. Every author, year, journal, volume and page range was verified against the primary record before publication; a DOI has been added to each entry, which the source did not carry. Entry 4 is an addition supporting the Tricine note above.

Laemmli, U. K. (1970). Cleavage of structural proteins during the assembly of the head of bacteriophage T4. Nature, 227(5259), 680–685. — Defines the Tris-Glycine discontinuous running buffer system that stacks and resolves proteins in denaturing SDS-PAGE. doi:10.1038/227680a0
Brody, J. R., & Kern, S. E. (2004). History and principles of conductive media for standard DNA electrophoresis. Analytical Biochemistry, 333(1), 1–13. — Review of how conductive-ion choice governs separation speed, voltage limits, and heat output, and of the long Tris-dominant history of DNA electrophoresis media. doi:10.1016/j.ab.2004.05.054
Lehrach, H., Diamond, D., Wozney, J. M., & Boedtker, H. (1977). RNA molecular weight determinations by gel electrophoresis under denaturing conditions, a critical reexamination. Biochemistry, 16(21), 4743–4751. — Establishes the rigorous denaturing conditions underpinning MOPS/formaldehyde-based RNA running buffers. doi:10.1021/bi00640a033
Schägger, H. (2006). Tricine–SDS-PAGE. Nature Protocols, 1(1), 16–22. — Added beyond the source list. The controlling protocol for the Tricine system, cited in the note under the chemistry table. doi:10.1038/nprot.2006.4

Buffer selection support. For help matching a running buffer to a gel system, a fragment size range, or a downstream recovery step, or for documentation requests, contact support@diagnocine.com. Ready to order? Back to the Gel Running Buffers catalog.

Satisfaction

Quality Rating

Value Rating

Style Rating

Subject