A method for normalizing results, the method comprising: (a) contacting a biological sample with a plurality of solid supports having binding members immobilized thereon that specifically bind an analyte in the biological sample, under conditions promoting binding of the analyte to the binding members, the solid supports being divided into subpopulations of supports that are differentiable from each other by a differentiation parameter, the binding members immobilized on each subpopulation binding to only one analyte in the sample; (b) contacting the biological sample with a solid support having a normalization factor immobilized thereon, the solid support being differentiable from the solid supports having binding members immobilized thereon; (c) contacting the solid support having a normalization factor immobilized thereon with a binding agent having binding affinity for the normalization factor and contacting the solid supports having binding members immobilized thereon with binding agents having binding affinity for each of the analytes, under conditions promoting binding of the binding agents to the normalization factor or analytes on the solid supports; (d) quantifying the binding agents bound to the solid supports, and correlating the quantity of binding agents with the differentiation parameters to obtain values individually representative of levels of the analytes and of the normalization factor, and (e) normalizing the values of the levels representative of the analytes to the value representative of the normalization factor, thereby correcting for variations in sample processing or biological matrix effects during performance of the method. (a) contacting a biological sample with a plurality of solid supports having binding members immobilized thereon that specifically bind an analyte in the biological sample, under conditions promoting binding of the analyte to the binding members, the solid supports being divided into subpopulations of supports that are differentiable from each other by a differentiation parameter, the binding members immobilized on each subpopulation binding to only one analyte in the sample; (b) contacting the biological sample with a solid support having a normalization factor immobilized thereon, the solid support being differentiable from the solid supports having binding members immobilized thereon; (c) contacting the solid support having a normalization factor immobilized thereon with a binding agent having binding affinity for the normalization factor and contacting the solid supports having binding members immobilized thereon with binding agents having binding affinity for each of the analytes, under conditions promoting binding of the binding agents to the normalization factor or analytes on the solid supports; (d) quantifying the binding agents bound to the solid supports, and correlating the quantity of binding agents with the differentiation parameters to obtain values individually representative of levels of the analytes and of the normalization factor, and (e) normalizing the values of the levels representative of the analytes to the value representative of the normalization factor, thereby correcting for variations in sample processing or biological matrix effects during performance of the method.