2.7 Analytical sensitivity: multiplex assays
The LOD of the multiplex assays was determined using ACTB as an IPC. To include ACTB in the multiplex assays, the template (PAC or the viral DNA/RNA) was serially diluted in the DNA extracted from the skin of healthy cattle, also referred to as negative skin DNA. The LODs were expressed either as copy number (PACs) or the highest detectable dilution (viral DNA/RNA) or the lowest detectable virus titer (TCID50/ml) per assay as described above (2.6).