Performance of microparticle-based SP-PLA and comparison with tube-based assay. a, comparison of microparticle-based (squares) and tube-based assay (diamonds) for detection of IL-6 (I), IL-8 (II), and VEGF (III) in buffer. All measurements were performed at least in triplicates. Error bars indicate SD. b, SP-PLA performance for detection of IL-6 (I), IL-8 (II), and VEGF (III) in buffer (squares), 10% serum (triangles), and 10% plasma (diamonds) with corresponding CV% values for every data point for buffer (open squares), 10% serum (open triangles), and 10% plasma (open diamonds). c, 2-fold dilutions of IL-8 in 10% plasma to estimate precision. The y axes display threshold cycle values of real time PCR assays; the x axes display concentrations of the investigated proteins in pm.