TABLE VI. Two-way analysis of variance (ANOVA) analysis for the application of the International Biological Reference Standard (WHO/NIBSC 09/186).

Two-way ANOVA of optical density/cutoff averages (test and dilution)
WHO/NIBSC 09/186
Source of variation	SS	DF	MS	F-value	p-value
Assay kit	73.55	6	12.26	6.22	0.013
Dilution	196.86	6	32.81	16.65	0.000
Residual	70.94	36	1.97
Total	341.34	48	7.11

DF: degree of freedom; MS: medium square; SQ: sum of squares.