Fig.5.

Measurement of protein–glycosaminoglycan interactions. Here 8mer saccharides derived from a partial heparinase I digestion of porcine mucosal heparin were spotted at different concentrations onto GAPS II microarray slides and incubated sequentially with 20 nM biotinylated protein–EGFP followed by AlexaFluor-546-labeled streptavidin. (A) Microarray image showing duplicate spots representative of 10 replicate spots. Contrast and brightness has been adjusted to show spot signal with respect to equivalent background signal. S9, siglec-9; −, streptavidin detection reagent applied to subarrays where no protein was incubated. (B) Graphs showing mean spot intensities against saccharide spotting concentration for different proteins. Spot intensity was normalized relative to background intensity by subtraction of the local background for each spot and the mean standard deviation of these values calculated for 10 replicate spots.