Slides were scanned at 5 μm resolution with an InnoScan 1100 AL fluorescence scanner (Innopsys, Carbonne, France). Image analysis was carried out with Genepix Pro 6.0 analysis software (Molecular Devices Corporation, Union City, CA) as previously described [14 (link),15 (link)]. Spots were defined as circular features with a diameter of 90 μm. Local background subtraction (median background) was performed and the background-subtracted median pixel intensity feature was used. To minimize the impact of noise on our comparisons, spots with intensity lower than 150 (1/2 the typical background signal when analyzing IgM and IgG at 1:50) were considered too low to be measured accurately and were set to 150. The average of duplicate spots was calculated to obtain a normalized value to the reference samples. A log-transformed (base 2) was applied for each slide, and the final data value was obtained from the normalized average of data from both wells for a given macaque sample. Full microarray data can be found in the Supplemental Table S1.