Figure 2: Design of the avian influenza cDNA microarray. Image of a spotted microarray containing four identical sub-arrays stained with SYBR Green II dye (Invitrogen; Carlsbad, CA).Each sub-array contains elements (2 spots/element) for three HA subtypes (HA5, HA7, HA9), three NA subtypes (NA1, NA2, NA3), M, and the Newcastle disease virus F gene, as a negative control. The genetic source of each genetic element is indicated.There are 32 spots per sub-array and 4 sub-arrays on each slide for a total of 128 spots, representing 16 unique genetic elements.