Agarose (CAS 9012-36-6) is a neutral linear polysaccharide purified from red seaweed and sold as a white powder for making agarose gels. In the lab, its main job is agarose gel electrophoresis — separating DNA or RNA fragments by size as they move through a porous gel under an electric field. For routine DNA work, labs typically dissolve 0.7–2.0% agarose powder in TAE or TBE buffer, heat until clear, cool, cast, and run. Choose powder by EEO, gel strength, melting/gelling temperature, and nuclease-free documentation — not by price alone.
What Is Agarose — and What Does Agarose Do?
Agarose is the purified, largely uncharged fraction of agar. Chemically, it is built from repeating units of D-galactose and 3,6-anhydro-L-galactose. That structure lets dry agarose powder dissolve in hot aqueous buffer and, on cooling, form a thermoreversible hydrogel with controllable pore size.
In practical terms, agarose does three jobs for molecular biology teams:
- Forms the gel matrix used in agarose gel electrophoresis
- Sieves nucleic acids by size so bands can be compared to a ladder
- Supports recovery and specialty workflows when low-melting-point (LMP) grades are selected
Monuo Chemical supplies Agarose identified as CAS 9012-36-6. See the Agarose (CAS 9012-36-6) product listing for sourcing discussions, or request a quote.
Chemical Identity at a Glance
| Item | Detail |
| Product name | Agarose |
| CAS Number | 9012-36-6 |
| Class | Linear polysaccharide (neutral agar fraction) |
| Typical form | White to off-white powder |
| Solubility behavior | Insoluble in cold water; dissolves on heating (~90°C+) |
| Primary lab use | Agarose gel electrophoresis of DNA/RNA |
| Related entities | TAE, TBE, EEO, gel strength, LMP agarose, DNA ladder, ethidium/SYBR stains |
How Agarose Gel Electrophoresis Works
An agarose gel is a porous network. When DNA (negatively charged) is placed in a well and voltage is applied, fragments migrate toward the anode. Smaller fragments move faster through the pores; larger fragments are slowed. After the run, bands are visualized with a fluorescent DNA stain under UV or blue light.
Why agarose — not random gelling agents — dominates this workflow:
- Low background charge when EEO is controlled → cleaner migration
- Tunable pore size via powder concentration
- Thermal hysteresis→ gel sets cool enough to cast, yet stays firm during typical runs
- Optical clarity for imaging bands
Agarose Powder Grades: Specs That Change Your Result
Procurement and core facilities should read the COA, not only the catalog name “electrophoresis agarose.”
| Specification | What it means | Practical target for routine DNA gels |
| EEO (electroendosmosis) | Residual charged groups that create buffer counter-flow | Often prefer low EEO (commonly discussed below ~0.13) |
| Gel strength (e.g. at 1%) | Mechanical firmness/tear resistance | Higher strength grades handle easier; check COA units |
| Gelling / melting temperature | Casting comfort vs fragment recovery options | Standard grades vs LMP for recovery workflows |
| Nuclease testing | DNase/RNase risk to sample integrity | Molecular-biology / nuclease-free claims need COA evidence |
| Moisture/packaging | Hygroscopic powder quality | Sealed, dry storage; avoid caked open stock |
Standard vs LMP vs Low-EEO Agarose
| Grade type | Best for | Buyer note |
| Standard electrophoresis agarose | Routine PCR checks, restriction digests, teaching labs | Most common cost-effective powder |
| Low melting point (LMP) | In-gel recovery / heat-sensitive enzymatic steps | Different melting profile; confirm on TDS/COA |
| Low-EEO / premium electrophoresis grades | Cleaner migration for demanding separations | Specify EEO window on the PO |
| Molecular biology / nuclease-tested grades | RNA work or integrity-critical nucleic acid workflows | Require nuclease statements on documents |
Agarose Recipe: Concentration Table for Gel Electrophoresis
This is the long-tail question most labs actually type: agarose recipe/agarose powder for gel electrophoresis. Use % w/v in electrophoresis buffer (TAE or TBE).
| Agarose % (w/v) | Typical DNA size window (approx.) | Common use case |
| 0.7% | ~1–25 kb (larger fragments) | Large PCR products / some genomic fragments |
| 1.0% | ~0.5–10 kb | Default starting point for many DNA gels |
| 1.5% | ~0.2–3 kb | Smaller amplicons / tighter resolution |
| 2.0% | ~0.1–2 kb | Very small fragments; watch gel stiffness/handling |
Example mini-recipe (illustrative): For 100 mL of a 1.0% gel, weigh 1.0 g agarose powder, add 100 mL TAE or TBE, heat until fully dissolved and clear, cool to roughly 55–65°C, pour into a leveled tray with a comb, and allow to set before loading. Always follow your lab’s validated SOP for stain, voltage, and buffer system.
Step-by-Step: Casting an Agarose Gel
- Choose a concentration from the table above based on expected fragment sizes.
- Weigh agarose powder; add to the correct volume of TAE or TBE in a flask with headspace.
- Heat until the solution is clear — incomplete dissolution causes cloudy gels and smeared bands.
- Cool before pouring so the tray/comb are not warped; avoid premature gelling in the flask.
- Insert comb; allow full set (often 20–40 minutes at room temperature).
- Transfer to the tank, cover with running buffer, load ladder + samples, run at your validated voltage.
- Image bands; dispose of stain-containing waste per local EHS rules.
TAE vs TBE — A Buyer-Relevant Buffer Note
TAE often supports faster migration with lower buffering capacity. TBE generally buffers longer runs and can sharpen some separations. Neither replaces correct agarose grade selection. Write the buffer system into the method so powder trials are comparable across lots.
Troubleshooting Agarose Gels
| Observation | Likely cause | What to change |
| Smeared bands | Incomplete dissolve; degraded DNA; overload; overheating | Re-melt fully; check sample integrity; reduce load |
| Gel tears / too soft | Low % or low gel-strength grade | Increase % or specify higher gel strength |
| Fuzzy/smiling bands | Uneven gel; hot run; buffer issues | Level cast; reduce voltage/heat; refresh buffer |
| No bands | Stain/imaging failure; failed PCR; wrong polarity | Verify stain + UV/blue light; check controls |
| Gel melts during run | Excess heat/voltage | Lower V; check buffer volume; confirm grade |
How Universities, Biopharma QC, and Institutes Should Specify Agarose
Put this on the RFQ so quotes are comparable:
- Product: Agarose | CAS 9012-36-6
- Intended use: agarose gel electrophoresis (DNA/RNA) — state grade if known (standard / LMP / low EEO)
- Need COA fields: EEO, gel strength, gelling/melting temps, purity/nuclease statements as required
- Pack size + expected annual volume
- Sample path: 5–20 g with COA before bulk commitment when qualifying a new source
Request documentation and a trial quantity via Request a Quote or info@monuochem.com. Product entry: Agarose CAS 9012-36-6.
Storage Notes for Agarose Powder
- Keep sealed, cool, and dry — agarose powder is moisture-sensitive.
- Avoid prolonged open-bin storage in humid prep rooms.
- Prepared gels are best used fresh; short refrigerated storage in buffer is common, but resolution drifts over time.
FAQ
What is agarose?
Agarose (CAS 9012-36-6) is a neutral polysaccharide powder purified from red seaweed. Labs dissolve it to cast agarose gels for electrophoresis and related separation workflows.
What does agarose do in gel electrophoresis?
It forms the porous gel that sieves DNA or RNA by size under an electric field, producing bands that can be compared to a molecular-weight ladder.
What agarose concentration should I use?
Start near 1.0% for many DNA fragments around 0.5–10 kb. Use ~0.7% for larger fragments and ~1.5–2.0% for smaller fragments. Validate against your ladder and method.
What is the difference between agarose powder and an agarose gel?
Agarose powder is the dry reagent. An agarose gel is the cast hydrogel made after dissolving powder in buffer and cooling.
Is electrophoresis agarose the same as food agar?
No. Electrophoresis agarose is purified for low interfering charge and documented specs (EEO, gel strength, often nuclease testing). Culinary agar is not a substitute for molecular biology gels.
What should I ask a supplier for before buying agarose powder?
Ask for CAS 9012-36-6 confirmation, COA with EEO/gel strength/thermal data, grade suitability for electrophoresis, packaging that protects from moisture, and optionally a 5–20 g evaluated lot before scale-up.
Where can I source Agarose CAS 9012-36-6?
Contact Monuo Chemical for Agarose (CAS 9012-36-6) with documentation support: product page · Request a Quote · info@monuochem.com.
Conclusion
If you only remember three controls for agarose work: match concentration to fragment size, match powder grade to EEO/thermal needs, and match COA fields to your QMS. That is how research institutes and biopharma labs keep gel electrophoresis reproducible when vendors change.
Ready to evaluate a lot? Request a 5–20 g sample + COA for Agarose (CAS 9012-36-6) via the contact page.
Related Resources
Disclaimer
Information is for laboratory reagent education and purchasing reference. Protocols are illustrative and must be validated under your institutional SOP, biosafety, and EHS rules. Verify each lot against the supplied COA and SDS.