Table 1. Dilution method for NIBSC standard.

Final concentration (EU/mL)	Final dilution factor	Dilution factor	Name	Sample (µL)	Dilution buffer (µL)
3.400	10	10	S	Standard 10	90
0.053	640	64	S1	S 16	1,008
0.027	1,280	2	S2	S1 500	500
0.013	2,560	2	S3	S2 500	500
0.007	5,120	2	S4	S3 500	500
0.003	10,240	2	S5	S4 500	500
0.002	20,480	2	S6	S5 500	500
0.001	40,960	2	S7	S6 500	500
-	0	0	S8	0	500

NIBSC, National Institute for Biological Standard and Control; EU, enzyme-linked immunosorbent assay unit.