New technique enables detection of low levels of sugars produced by living organisms

Tiny amounts of carbohydrates (1 zmol, correspnding to a few hundred molecules) can be detected quantitatively by a real-time method based on the conjugation of carbohydrates with DNA marker.

The  method called glyco-qPCR uses amplification to provide uniform, ultrasensitive detection of carbohydrates, which can be applied to glycobiology, as well as carbohydrate-based drug discovery.

Researchers at Rensselaer Polytechnic Institute have developed an ultrasensitive method for detecting sugar molecules - or glycans - coming from living organisms, a breakthrough that will make possible a more detailed understanding of cellular functions than either genetic or proteomic (the study of proteins) information can provide. The researchers hope the new technique will revolutionise the study of glycans, which has been hampered by an inability to easily detect and identify minute quantities of these molecules.

''The glycome is richer in information than the genome or the proteome. A cancer cell, for example, might have the same genome as a non-cancer cell, but it produces different sugars,'' says Robert Linhardt, the Ann and John H. Broadbent Jr '59 Senior Constellation Professor of Biocatalysis and Metabolic Engineering at Rensselaer, and an author of the study.

Linhardt explains, ''Until now, the stumbling block in glycomics has been rapid and sensitive determination of the glycans present in a biological sample, and up to now we were very limited by how much we could detect. With this technique that we've developed, Glyco-qPCR, we can detect a very small number of molecules and that should accelerate the growth of the field.''

The new technique is discussed in a paper titled Signal Amplification by Glyco-qPCR for Ultrasensitive Detection of Carbohydrates: Applications in Glycobiology, which was published in the 16 October online edition of Angewandte Chemie International. Linhardt and Jonathan Dordick, director of the Rensselaer Center for Biotechnology and Interdisciplinary Studies (CBIS), vice president for research, and the Howard P. Isermann '42 Professor of Chemical and Biological Engineering, were joined in the research by Seok Joon Kwon, Kyung Bok Lee, Kemal Solakyildirim, Sayaka Masuko, Mellisa Ly, Fuming Zhang, and Lingyn Li.