CHEMICAL METHYLATION OF AGAROID HYDROXYL-GROUPS

Partially methylated derivatives of agar or agarose were prepared by m ethylating an agar or agarose with various levels of natural methylati on in alkaline solution with dimethyl sulfate. The resultant derivativ es were analysed for methylation pattern, gel setting temperature, and gel strength. The extent to which the gelling temperature was lowered was proportional to the level of methylation at the 2-position of the D-galactosyl residues. Since the 2-hydroxyl group on the D-galactose is the only hydroxyl group which has a binding function in the double helix model, this observation is strongly supportive of this model of agarose gels.