Fig 2. Simultaneous detection of ASPV, ApMV and ASGV by multiplex RT-qPCR in three different copy number combinations of standards.

Multiplex RT-qPCR amplification plots in samples containing a high copy number of each of the two targets mixed with a relatively low copy number of the third target and diluted in RNA derived from virus negative tested apple tissue. A, ASPV at a low copy number concentration; B, ASGV at a low copy number concentration; C, ApMV at a low copy number concentration. Estimated copy numbers are denoted in parentheses. Threshold lines presented, correspond to the low copy number targets.