Microarray data processing and analysis

The microarrays were scanned at 70% photomultiplier tube and 100% laser power settings using a Genepix 4000B confocal scanner (Axon Instruments, Sunnyvale, CA). Genepix 3.0 software (Axon Instruments) was used to analyze the acquired images at 532 nm for Cy3 detection. The average background was subtracted and the values < average background ±2 standard deviation (SD) were removed from each data point. Median of the effective data points of each lectin was globally normalized to the sum of medians of all effective data points for each lectin in one block. Each sample was observed consistently by three repeated slides and the normalized medians of each lectin from nine repeated blocks were averaged and the SD was determined. The normalized data of each sample were compared with each other based upon fold-changes according to the following criteria: fold changes >2 or <0.5 indicated an up-regulation or a down-regulation, respectively. Differences between the two arbitrary data sets or multiple data sets were tested by Student's t test or one-way ANOVA to each lectin signal using SPSS v. 19. The original data was further analyzed by Expander 6.0 (http://acgt.cs.tau.ac.il/expander/) in order to perform a hierarchical clustering analysis.