A competitive ELISA based on nanobodies for the detection of serum neutralizing antibodies against porcine epidemic diarrhea virus

Table 3 Optimized dilution of pig sera tested by the developed cELISA

No. serum	Sera type	Different dilutions of pig sera
No. serum	Sera type	1:10	1:20	1:40	1:80	1:160
1	Positive	0.128	0.199	0.320	0.562	0.689
	Negative	1.134	1.123	1.12	1.119	1.115
	P/N	0.113	0.177	0.286	0.502	0.618
2	Positive	0.323	0.413	0.687	0.907	1.005
	Negative	1.231	1.229	1.204	1.194	1.191
	P/N	0.262	0.336	0.571	0.760	0.844
3	Positive	0.135	0.165	0.257	0.443	0.566
	Negative	1.031	1.024	1.018	1.021	1.014
	P/N	0.131	0.161	0.252	0.434	0.558
4	Positive	0.264	0.278	0.397	0.523	0.704
	Negative	1.065	1.054	1.058	1.061	1.058
	P/N	0.248	0.264	0.375	0.493	0.665
5	Positive	0.424	0.528	0.653	0.928	1.070
	Negative	1.047	1.134	1.134	1.134	1.134
	P/N	0.405	0.466	0.576	0.818	0.944