RT and qPCR were performed using the AgPath-ID Onestep RT-PCR kit (Applied Biosystems, Inc., Foster City, CA) and the LightCycler 480 and software version 1.5.0.39 (Roche Applied Sciences). The forward primer was MeN_TMF(5′-GCGAGAGCTGCCCATCTTC), the reverse primer was MeN_TMR (5′-ACTCCGTTGCAGTGTCAATGTC) and the forward MeN_TMP probe was (6-FAM)~AACCGGCA CACCC~(NFQ), with the fluorogenic probe located in the region bracketed by forward and reverse primers. Cycling conditions were 45°C for 10 min, 95°C for 10 min, and 45 cycles of 95°C for 15 s and 60°C for 45 s, followed by 40°C for 2 min. The standard curve and RT-qPCR parameter determination was performed using an in vitro transcript RNA template with the sequence of the N gene of the measles vector. MV1-F4 suspension (GSK; EF4MA001A, viral titer 4.2 log CCID 50 /ml, 7.2 log genome equivalent (geq)/ml, diluted to 10 4 copies geq), was used as positive extraction control. Negative (RNase/DNase free H 2 O) and positive extraction controls were run in quadruplicate and duplicate reactions, respectively. MV1-F4 RNA recovery was assessed by N-specific RT-qPCR after spiking each type of tissue with MV1-F4 at various concentrations, and ranged from 90 % to 100 %. The presence of MV1-F4 RNA was considered positive if the measurements exceeded the limit of detection (LOD) of 100 geq/reaction, and if the acceptance criteria (error <0.2, efficiency>90 % and crossing point <45) were fulfilled. The LOD was defined as the lowest amount of copies that can be detected (but not necessarily quantified as an exact value) with 95 % probability. All samples were tested once.