ABSTRACTRecently we evaluated a custom TaqMan array card (TAC) detection system, formerly known as a TaqMan low-density array (TLDA) card, for simultaneous real-time PCR identification of 21 pathogens and three control targets in duplicate from respiratory specimens (M. Kodani et al., J. Clin. Microbiol. 49:2175–2182, 2011). We engineered an adaptable and expandable system of in vitroRNA transcripts to serve as a combined positive control for both DNA and RNA targets in multiple-pathogen-detection technologies based on real-time reverse transcription-PCR.