gelling agent for microbiological culture media
Alternative to Agar
GELRITE® is a highly-purified, natural heteropolysaccharide which forms stable, agar-like gels when exposed to soluble salts. Compared to agar however, only about half the amount is required.
GELRITE® has been specially developed as a gelling agent for microbiological culture media. It can however, replace agar in other applications, too.
Polymerisation of GELRITE® is enhanced in the presence of (bivalent) kations. It is therefore supplemented by MgCl2 if a solid gel structure is required. Elevated salt concentrations increase gelling temperature (e.g. 500 mM Na+ to approx. 68 °C with 1 % GELRITE®). When using very high salt concentrations like e.g. seawater, gelling capacity may be significantly reduced.
Linear polysaccharide comprising of O-acetylate glycuronic acid, glucose
and rhamnose units.
Advantages of GELRITE® compared to Agar:
- consistent product quality
- almost 100 % batch-to-batch conformity
- forms remarkably clear gels
- reduces preparation time as gels form faster
- remains stable even at high temperatures and is therefore also ideal for thermophilic microorganisms; gels can withstand repeated autoclaving without any changes to gel strength
- indicates no toxic contaminations
(e.g. through phenols, as found in agar)
- is chemically inert against most media additives
- is resistant to enzymatic degradation
- is non-toxic (no signs of toxicity in rats exposed to a dose
of 5.000 mg/kg)
- is very economical to use