Routine Services

Molecular Weight

The approximate molecular weights of polysaccharides are measured using size exclusion chromatography (SEC). The molecular weights of oligosaccharides are measured by MALDI-MS, either non-derivatized or after derivatization.

Molecular Weight Determination and Purification of Polysaccharide by HPLC

Molecular weight determination of polysaccharide by size exclusion chromatography; purification of the polysaccharide according to its molecular weight for further structure analysis (glycosyl composition, glycosyl linkage or NMR, et al)

Methods Used

High performance liquid chromatography (HPLC) is used for size exclusion chromatography (SEC) using Refractive index (RI), U.V or ELSD or fluorescent detectors.

Amount of Sample Required for Analysis

If you have no knowledge of the nature of the sugar constituents of your sample and you desire an ideal analysis, a minimum of 500 micrograms of carbohydrate is required. If you have considerably smaller amounts of carbohydrate sample, we can make special arrangements to determine the composition of your sample. Please contact us to discuss your specific requirements, and do not let limited sample amount deter you from requesting our services.

Size exclusion chromatography (SEC) graph

Size exclusion chromatography (SEC) of a lipopolysaccharide sample under (A) detergent conditions on Superdex-75 and (B) non-detergent conditions on Superose-12.

Molecular Weight Determination of Oligosaccharides

Determination of the molecular weight and structure of oligosaccharides in glycoproteins.

Methods Used

We can use Matrix-Assisted Laser Desorption Ionization-Mass Spectrometry (MALDI-MS) or Electrospray Ionization-Mass Spectrometry (ESI-MS). Oligosaccharide structures are then determined from the molecular weights generated by mass spectrometry. The structure of a glycan can be confirmed by fragmentation of the parent ion (msn).

Amount of Sample Required for Analysis

A minimum of 50-100 micrograms of carbohydrate is required, more if available. Clients may also submit purified oligosaccharides to the laboratory for glycan profiling.

General Criteria for Sample Preparation

Your sample should be pure, soluble in water or volatile organics, and free of non-volatile salts, buffers, and detergents.