Agar & Agarose

Few materials change state as politely as agar. Stir a little of it into hot water and the solution stays liquid while it is warm; let it cool and it sets into a firm, transparent gel; heat it again and it melts. Red seaweed has been building this thermoreversible trick for millions of years, and laboratories and factories have been using it for well over a century — from the culture plate to the electrophoresis gel.

Eata Marisource supplies the full agar family from red seaweed — agar, purified agarose, and agar and agarose oligosaccharides — all as research and industrial grades with documented gel data. The material you evaluate at bench scale is the material you can scale with.

The Ocean's Thermoreversible Gel

Agar is a mixture of two polysaccharide families extracted from red seaweed: neutral agarose, which is responsible for the gelling, and the charged agaropectin fraction that carries sulfate and other groups. In solution, agarose chains wind into double helices on cooling and bundle into a three-dimensional network, which is why gels form at concentrations as low as 0.5%. The same physics explains the wide hysteresis buyers notice: a typical 1.5% gel sets around 32–45 °C but does not melt until roughly 80–95 °C.

Thermoreversible — sets on cooling, melts on reheating, cycle after cycle
Low use level — firm gels from 0.5% to 2% depending on grade
Two fractions — neutral agarose for gels, charged agaropectin in broad agar grades
Wide hysteresis — set at 32–45 °C, melt at 80–95 °C

The Agar & Agarose Line

The supply program covers three product categories, each with its own grade logic:

Product Category	Typical Source	Typical Forms & Grades
Agar	Gelidium, Gracilaria	Powder, strip, flake; 400–1300 g/cm² gel strength
Agarose	Purified from agar	Low-EEO, molecular biology, low-melting grades
Agar & Agarose Oligosaccharides	Enzymatic or acid hydrolysis	DP 2–6 fractions, lyophilized powder

Each line is released with lot-level data covering gel strength, setting and melting temperature, moisture and ash, so the analytical picture matches the product.

Agar — the Broad-Gel Grades

Agar grades are defined first by source and then by physical form. Gelidium-derived agar is prized for high gel strength and clarity; Gracilaria agar is the standard workhorse for general gelling. Both come as powder, strip and flake, with gel strength spanning roughly 400 g/cm² for strips to over 1300 g/cm² for superfine powder at 1.5% concentration. Moisture, ash and heavy-metal limits are controlled per grade.

Figure 1. Red seaweed — the raw material behind agar and agarose.

Gelidium and Gracilaria grades — source documented per lot
Forms — powder, strip and flake for different dissolution workflows
Gel strength — 400 to 1300+ g/cm² at 1.5%, graded and verified

Parameter	Typical Value
Appearance	White to pale yellow powder, strip or flake
Gel strength (1.5%)	400–1300 g/cm² depending on grade
Gelation temperature	32–45 °C
Melting temperature	80–95 °C
Moisture	≤ 12–18%
Ash	≤ 5–6.5%

Translucent agar flakes in a glass bowl.

Figure 2. Agar in flake form — the semi-refined polymer before milling and purification.

Agarose — the Purified Fraction

Agarose is agar refined to the neutral gelling fraction, and it is the form the molecular biology lab reaches for. Research grades are defined by electroendosmosis (EEO), gel strength and transition temperatures: low-EEO agarose with EEO around 0.09–0.13 is the standard for electrophoresis, with gel strength of at least 1200 g/cm² at 1% and a gel point near 36 °C in a 1.5% gel. Low-melting and ultra-low-gelling agarose are available where DNA recovery or temperature-sensitive work demands softer transitions.

Figure 3. Agarose gel slab on a light box — the standard tool for electrophoresis research.

Low-EEO agarose — EEO 0.09–0.13 for clean electrophoretic separations
Molecular biology grade — defined gel strength and transition data
Low-melting options — for DNA recovery and temperature-sensitive assays

Parameter	Typical Value
CAS	9012-36-6
EEO	0.09–0.13 (low EEO)
Gel strength	≥ 1200 g/cm² (1% gel)
Gel point	36 °C ± 1.5 °C (1.5% gel)
Moisture	≤ 10%
Molecular weight	~80,000–120,000 Da

Hot agar solution poured into a petri dish.

Figure 4. Hot agar solution being poured — the thermoreversible gelling step.

Agar & Agarose Oligosaccharides

The third category moves down the molecular scale. Agar and agarose oligosaccharides are short-chain fractions produced by enzymatic digestion with beta-agarases or by controlled acid hydrolysis, with the degree of polymerization tuned by the preparation conditions. Typical fractions run from neoagarobiose at DP 2 through neoagarotetraose at DP 4 to neoagarohexaose at DP 6. Because they are short and water-soluble, these oligosaccharides behave differently from the parent gels and support their own line of research.

Figure 5. Agarose gel plugs in a petri dish — cut from a solidified slab for analytical work.

DP-defined fractions — neoagarobiose (DP2) to neoagarohexaose (DP6)
Enzyme or acid route — preparation documented per lot
Water-soluble — short chains with defined analytical data

Parameter	Typical Value
Product class	Agar / agarose oligosaccharides
Degree of polymerization	DP 2–6 (custom ranges on request)
Preparation	β-agarase digestion or controlled acid hydrolysis
Appearance	White lyophilized powder
Analysis	HPAEC-PAD, FT-IR, GPC documented per lot

Where These Gels Earn Their Place

Agar family products serve two very different worlds, and both are worth covering. Typical deployment patterns include:

Electrophoresis and molecular biology — agarose slabs, low-melting recovery grades
Microbiology and culture media — agar as the standard solidifying agent
Food and texture research — agar gels in structure and stability studies
Prebiotic and gut-microbiota research — agar oligosaccharides in fermentation studies
Plant tissue culture and diagnostics — defined-gel media and assay supports

Figure 6. Set agarose gel in sample jars — translucent, stable and ready for evaluation.

Documentation and Data on Request

Every lot is released with a certificate of analysis covering gel strength, setting and melting temperatures, moisture, ash and heavy metals. Electrophoresis grades add EEO and transition-temperature data; oligosaccharide fractions ship with chromatographic and FT-IR evidence. MSDS and technical data sheets are provided with each shipment, and evaluation samples are supplied for R&D screening before volume commitments.

Customization — Matching the Gel to the Application

Gel programs are usually specific about gel strength, form and transition temperature, so our customization service covers:

Gel-strength targeting — grades from soft culture media to high-strength superfine powder
Form adjustment — powder, strip, flake or pre-set gel presentations
Grade selection — broad agar, low-EEO agarose or low-melting agarose by application
Oligosaccharide ranges — DP fractions tailored to your assay or formulation
Documentation — certificate parameters and test methods aligned to your internal specification

From a firm agar culture plate to a low-melting agarose gel, the family is defined by the same elegant chemistry — and each grade needs different supply care. Request a sample and full documentation from Eata Marisource to test the material in your own application.

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