End-label free-solution electrophoresis of the low molecular weight heparins.

The intact heparins are highly charged oligosaccharides. Their charge polydispersity and the possible occurrence of numerous isomers complicate the analysis of these biomedically important glycoconjugates. After unsuccessful attempts to resolve the low molecular weight heparins in entangled matrixes, or through the use of counterions (Stefansson, M.; Novotny, M. V. Anal. Chem. 1994, 66, 3466-3471), we have designed a unique end-label reagent to incorporate both a fluorescent moiety and a desirable frictional increment to the analyte molecules. The resolution of small oligomers was improved dramatically following this approach. We also propose a scheme, based on the end-label free-solution electrophoresis model (Mayer, P.; Slater, G. W.; Drouin, G. Anal. Chem. 1994, 66, 1777-1780), that could potentially predict the migration times of some oligomers of complex heparin mixtures.