Ranking of biological samples is similar using kits from the different manufacturers.

For each analyte and biological sample the data obtained with kits from the different manufacturers I (green), II (red), III (blue) and IV (pink) was plotted in a radar or spider plot with the stimuli at the corners of the plot. The geometric mean of all data-points (n = 5) for results from the different labs and kit lots is shown per sample using the manufacturer’s standard values and detection label. Results above the standard curve were set at 10 000 pg/ml.