The use of multiplex platforms for absolute and relative protein quantification of clinical material

When introducing multiplex platforms to measure protein content in precious clinical material there is an increased risk of cross reactivity, loss of sensitivity as well as accuracy. In this paper, four multiplex platforms and one singleplex platform were compared by running pre- and post-treatment plasma samples from CML patients. We found a variation of absolute protein concentrations between platforms. For some of the analytes and platforms, relative differences between pre- and post-treatment samples correlated. We conclude that absolute concentrations measured by different platforms should be compared with caution and comparing relative differences could be more accurate.