Agarose

In a gel electrophoresis run, the matrix has exactly one job: stay out of the way. Any stray charge built into the gel drags buffer toward the cathode, smears the bands and quietly ruins resolution. Agarose is what you get when agar is stripped down to its neutral fraction, and that neutrality is why it became the standard medium for separating everything from 50-base PCR products to 10-megabase chromosomal DNA. Eata Marisource supplies purified agarose in the grades working laboratories actually order, from routine low-EEO powder to low-melting formulations and cross-linked bead media for column work.

Sourcing matters with this product more than most. Agarose is refined from the agar of Gelidium and Gracilaria seaweeds, and batch quality swings with the raw material, the de-sulfation process and the finishing steps. We bridge that variability with lot-level certification of the four numbers that decide whether a gel works: gel strength, gelling and melting temperatures, and electroendosmosis.

From Seaweed to a Charge-Neutral Matrix

Agar is actually two polysaccharides: the gelling fraction we call agarose, built from alternating β-D-galactose and 3,6-anhydro-α-L-galactose units, and agaropectin, which carries the sulfate and pyruvate groups responsible for unwanted charge. Making agarose means removing agaropectin and washing out the ionic residues until sulfate falls below 0.1–0.2% and the electroendosmosis value drops under 0.13. What survives is a high-molecular-weight (roughly 120,000–310,000 Da), thermally reversible hydrogel with an unusually wide gap between its gelling point (around 36°C) and its melting point (around 88°C), which is what lets you pour gels comfortably and run them without watching them soften.

Grades We Keep in Stock

Each grade is tuned for a different question, and the specification table tells you which one answers yours:

Four Numbers That Define an Agarose

• Gel strength: the force needed to fracture a 1% gel. Above 1200 g/cm² you get trays that lift cleanly and wells that do not tear during loading.
• Gelling vs melting temperature: the wider the hysteresis, the easier the handling. Standard grades set at ~36°C and melt near 88°C; low-melt grades reverse the logic and liquefy at 65°C so DNA survives re-melting.
• Electroendosmosis (EEO): measured as the –mr value, it quantifies the counter-ion drag inside the gel. Lower EEO means sharper bands and truer migrations.
• Sulfate content: the purity proxy. Less sulfate, less charge, less background when the gel is stained.

Matching Concentration to Fragment Size

One more number belongs to the customer: gel percentage. As a working guide for our LE grade in 1X TAE or TBE:

Below 0.5% the gel becomes fragile even at high gel strength, and above 2% the pores get too tight for anything but short fragments; specialty grades take over from there.

How Our Agarose Is Refined

Raw Gelidium and Gracilaria are washed and alkali-pretreated to convert L-galactose-6-sulfate residues into 3,6-anhydrogalactose, then extracted in hot water. Agaropectin is precipitated selectively from the extract, and the agarose-rich phase is further de-sulfated over ion-exchange media, bleached without organic solvents, filtered, and dried before milling to a free-flowing white powder. The same purified stream feeds our bead plant, where droplet gelation and cross-linking produce the spherical 2B/4B/6B media. Nuclease-free grades are filled and certified without ever exposing the powder to biological-material handling areas.

Certification on Every Lot

• Appearance: white, homogeneous, free-flowing powder; pH 6.0–7.5 (1% solution)
• Gel strength at 1% and 1.5%, gelling and melting temperatures per grade
• EEO (–mr) and sulfate content within grade limits
• Moisture ≤7–10% and ash ≤4% depending on grade
• Clarity of a 1.5% gel (≤3 NTU) and low gel background after staining
• DNase, RNase, protease and endonuclease activity: none detected on molecular-biology grades

Where Our Customers Use It

Routine and preparative nucleic-acid electrophoresis remain the anchor applications, followed by blotting workflows and gel-extraction protocols that depend on low-melt chemistry. Immunology labs run Ouchterlony plates and radial immunodiffusion on our large-pore grade, while genomics facilities reach for PFGE agarose when fragments outgrow conventional gels. The cross-linked bead media serve a different clientele entirely: process chromatography teams packing size-exclusion columns, and conjugation chemists coupling Protein A, Ni-NTA, streptavidin or custom ligands onto the activated base matrix. Enzyme immobilisation and 3D cell-embedding round out the industrial side.

Packing and Documentation

• Powders: 25 g, 100 g and 500 g bottles, plus 1 kg, 5 kg and 25 kg fibre drums for bulk users
• Bead media: 100 ml to 10 L packs shipped in 20% ethanol slurry, stored 4–30°C, never frozen
• Every lot ships with a COA covering gel strength, gelling/melting points, EEO, sulfate, moisture and nuclease results; MSDS and TDS included
• Powder stores at room temperature in a dry place; opened bottles should be resealed tightly against humidity

Custom Grades on Request

Catalogue grades cover most benches, but not all. If your protocol needs a specific gel strength window, a tighter EEO limit, a particular particle-size cut for the beads, or private-label bottling in your own sizes, tell us the target specification and the application behind it. We can screen development lots against your in-house method and scale the winning formulation from kilogram quantities to full production batches.

For Research or Industrial Raw Materials, Not For Personal Medical Use!