Five key protocol variables were systematically assessed: (i) the applied trypsin concentration, (ii) the incubation time for proteolytic activation of the RV, (iii) the infection dose applied, (iv) the duration of neutralization time and (v) sample-specific factors that affect assay performance.
Furthermore, correlation studies was done between several sample materials and Virus neutralization (VNA) and immunofourescence assay titers. Moreover the sensitivity limit and the linearity of the VNA was determined as well as intra- and inter-assay repeatability.
