An analytical approach to reduce between-plate variation in multiplex assays that measure antibodies to Plasmodium falciparum antigens

Table 2 Reduction of between-plate variation for MFI on the linear and natural-log scales

Antigen	Linear scale					Natural-log scale
Antigen	Unadjusted variance	Adjusted^a (I = 5) to unadjusted ratio	Adjusted^b (I = 6) to unadjusted ratio	Adjusted^c (I = 6) to unadjusted ratio	Adjusted^d (I = 7) to unadjusted ratio	Unadjusted variance	Adjusted^a (I = 5) to unadjusted ratio	Adjusted^b (I = 6) to unadjusted ratio	Adjusted^c (I = 6) to unadjusted ratio	Adjusted^d (I = 7) to unadjusted ratio
Recombinant protein
AMA-1	139,412	1.183	1.079	1.160	1.077	0.0013	1.024	0.912	1.026	0.925
EBA175	125,497	1.013	0.966	1.269	1.151	0.0060	1.030	0.900	1.083	0.943
MSP1	167,994	0.905	0.889	0.992	0.957	0.0121	0.609	0.598	0.598	0.606
MSP2	759,821	0.928	0.927	0.873	0.863	0.0070	0.849	0.844	0.751	0.759
MSP3	676,301	0.887	0.725	0.874	0.733	0.0076	0.801	0.658	0.903	0.631
FV2	2,679,797	0.659	0.539	0.576	0.506	0.0739	0.473	0.445	0.452	0.444
Gene expression protein
MSP11	37,028	0.842	0.875	0.811	0.850	0.0021	0.862	0.894	0.830	0.869
Pf41	170,559	0.621	0.596	0.615	0.600	0.0155	0.279	0.289	0.288	0.299
Synthetic peptide
CSP	157,499	0.742	0.760	0.727	0.743	0.0355	0.400	0.395	0.369	0.372

The ratios assess the variance reduction of the different adjustments with values less than one indicating a reduction of between-plate compared to the unadjusted values.
^aAdjustment using 5 pooled controls from pre-screened samples (PC1–PC5)
^bAdjustment using 6 pooled controls including the pooled negative female control (PC1–PC5 plus US-NC)
^cAdjustment using 6 pooled controls including the pooled negative male control (PC1–PC5 plus FV2-NC)
^dAdjustment using all 7 pooled controls

ISSN: 1475-2875