Book excerpt: The analysis of Cultural Heritage samples is critical for the understanding of the arstists' technique, the conservation and restoration of artworks. These objects under investigation are rare and precious and the amount of sample available for the analysis is usually very low, thus implying the development and the optimization of adapted analytical methodologies. The objective of this PhD was to develop new analytical methods to study glycoproteins and polysaccharides from plant gums in Cultural Heritage samples.These macromolecules have been separated by size exclusion chromatography and modified polyacrylamide gels, which allowed to reveal the presence of proteins with molecular weights up to 1-2 million Dalton. A novel analytical strategy based on mass spectrometry allowed to obtain the caracteristic fingerprint of each plant gum. This developed method was successfully applied on a watercolor sample dated from 1870 supplied by the Metropolitan Museum of Art (New York, USA).