Carbohydrate analyses are performed after hydrolysis in 4N trifluoroacetic acid at elevated temperatures. The monosaccharides released by this process are resolved by chromatography on a Dionex BioLC and detected by pulsed amperometry at alkaline pH. Quantitation is obtained by comparison to a standard carbohydrate mixture. All neutral and amino sugars may be identified and quantitated using our extensive library of compounds. Amino sugar analyses may also be determined on the amino acid analyzer after a short acid hydrolysis in 6N HCl. Analysis by pre-column derivatization is performed on an ABI model 420H amino acid analyzer by the PTC method after gas phase acid hydrolysis in the instrument.
Techniques are also available for identification of tryptophan residues.
Analysis by post-column derivatization is performed on a Beckman model 6300 amino acid analyzer. This method is particularly appropriate for high accuracy analysis and for physiological amino acid analysis. Peptides and proteins having initial yields in the range of 10 to 100 picomoles may be sequenced effectively. Various chemical modifications are available to identify unusual or labile residues. Mass spectrometry of proteins and peptides is a rapidly expanding service of the core.