FIG. 1.

(A) Layout of oligonucleotide probes on the array (size 0.6 × 0.4 cm). The universal bacteria probes PB1, PB2, and PB3 were designed from a conserved region at the 16S rRNA gene. Dots labeled Psu, Aci, and Klb are the genus-specific probes that are used to identify Pseudomonas, Acinetobacter, and Klebsiella spp., dots labeled M are position markers (an irrelevant digoxigenin-labeled oligonucleotide), and those labeled NC are negative controls composed of the tracking dye only. (B) The universal probes PB2 and PB3 can be used to assess the bacterial bioburden by standardized signal intensities (a.u., arbitrary unit) and to grade the contamination severity.²⁹ Probe sequences for all dots are listed in the table (inset).