Nested amplification of 10-fold serial dilutions of the G1 and P[8] dsRNA positive control transcript with VP7 and VP4 1st and 2nd round primers. Lanes: molecular weight marker (lane 1), 10−3–10−14 transcript dilutions (lanes 2–13) as indicated on the upper part of the lane. Numbers on the lower part of each lane (scientific notation) indicate copies per qRT-PCR reaction. Amplicon sizes for first and second round VP7 amplification are 333 bp and 193 bp and for VP4 amplification, 257 bp and 214 bp, respectively. 1st and 2nd round reactions were visualized using a LabChip® GX instrument (PerkinElmer, Inc., Waltham, MA).