Methods for making microarrays and their uses

The present invention provides microarrays that can be analysed by more than one technique using a non-covalent ligand attachment strategy to solid supports such as indium tin oxide (ITO) covered transparent glass slides. This provides, inter alia, glycan arrays on a micrometer scale which allow multimodal readout by MALDI-Tof-MS, fluorescence and optical microscopy. Glycans functionalized with a C5-aminolinker were attached in situ on a picomolar scale to a hydrophobic tag bound to this surface, thus avoiding the wasteful off-chip ligand tagging of other approaches. Glycan arrays prepared using this methodology were analysed both with a fluorescence scanner and by on-chip MALDI-mass spectrometry in a series of glycomics experiments specifically requiring a multimodal readout.