Development of reliable multiplex assays on xMAP beads for serological or other assays, is not only dependent on proper coupling of capture molecules, it is also dependent on the proper mixing of multiple bead regions into multiplex bead mixes.  

Several excel based workbooks are available to assist with insuring the most precise coupling of molecules using different ug/million beads or picomols/million beads coating levels.  These workbooks insure the accuracy of calculating the volumes of reagents needed at different concentrations to maintain the stoichiometry of all reagents even with scaling up.  In addition several excel based tools are available to precisely calculate how to make multiplex mixes for any assay configuration.