Figure 2From: Pseudo-plaque reduction neutralization test (PPRNT) for the measurement of neutralizing antibodies to Crimean-Congo hemorrhagic fever virusCorrelation of the mean neutralizing titers of 69 serum samples determined by FFRNT and PPRNT. Based on the distribution, a positive cut-off value of 1:4 was defined for PPRNT and FFRNT. The solid line indicates complete correlation.Back to article page