Figure 8.

Selection of blocking reagents for the carbohydrate microarray on the hydrazide-dendrimer coated slide. GlcNAcβ1-4GlcNAc arrays were spotted on hydrazide-dendrimer coated slides (12 replicates per slide), and subjected to 10 min microwave treatment and the slides were blocked with one of the blocking reagents before immunoassay: (1) Superblocking buffer from Pierce; (2) 0.1 × PBS buffer containing 1% BSA, 0.1% Tween 20; (3) 0.1 × PBS buffer containing 3% casein, 0.1% Tween 20; and (4) 0.1 × PBS buffer containing 3% nonfat milk. The immunoassay fluorescent signals were obtained by incubation of the microarray with 35 µL of cocktail solution containing 1 µg/mL of Biotin-WGA and Cy3-Streptavidin solution in a 0.1× PBST solution at 30 °C for 60 min. The microarrays were washed with PBST buffer for 5 mins twice and 0.01 ×PBS for 1 min before they scanned with confocal scanner under identical layer power and PMT. The noise signal was determined to be the fluorescent intensity around the spots. Each data shown represent means ± SD of 48 replicates from four slides.