Hybridization of CDR3β-specific microarrays. Panel A. Cy3/FITC overlay image of Cy3-labeled A. thaliana LTP4 synthetic target (red) hybridized to 108 CDR3β-specific probes. Black arrows indicate negative controls, printing buffer with FITC-labeled tracking oligonucleotide (green) but no CDR3β-specific probe. Panel B. Cy3/FITC overlay image of Cy3-labeled IRSS clonotype 21 synthetic target (red, indicated by white arrow) hybridized to 108 CDR3β-specific probes. Outer columns of each subarray are negative controls. Note hybridization specificity.