2.2.5. Recovery efficiency and repeatability of the concentration
procedure
An intra-laboratory assay was performed to test the repeatability
of the concentration method. Briefly, 200 L of seawater, river
water or mineral water spiked with HAdV35 and NoV GGII.13 was
mixed in a large plastic container. Water was mixed by manual
stirring, acidified and then distributed into twenty 10-L sample
containers. This procedure was repeated for each matrix and
included mineral water as a control. Viral particles were concentrated
as described in 2.2.1. HAdV and NoV GGII.13 were quantified
by qPCR and qRT-PCR after nucleic acid extraction, respectively.
Additionally, indigenous JCPyV was quantified in the 20 seawater
replicates.