Sialylation sensitive bands in the Raman spectra of oligosaccharides and glycoproteins

N-Acetylneuraminic (sialic) acid which plays a key role in process of cell recognition and interaction was studied by Raman spectroscopy. It was revealed that the strong band at 873cm−1 arising from the glycerol fragment vibrations can be used as a Raman marker of sialic acid. In the Raman spectra of oligosaccharides and glycoproteins this band is observed at 880cm−1. The strong dependence of the 880cm−1 band intensity on the sialic acid (Sia) content in α 1-acid glycoprotein was shown. The data demonstrate the possibility to use Raman spectroscopy approach as a simple and non-destructive assay for the rapid registration and quantification of Sia in the glycoproteins and on the membranes of the living cells.