Quantification of protein expression in cell culture supernatants by BD Cytometric Bead Array (CBA). Confluent monolayers of HBMECs were coincubated with Pf-IRBCs or Pf-IRBC-Ps for 6 hours and supernatants were assayed by CBA (BD Cytometric Bead Array). Control HBMECs and HBMECs coincubated with RBCs showed very little to no protein. Protein levels of IL-6 (A) and IL-8 (B) were detected in high range, which is in accordance with their mRNA levels as detected by microarray experiments. Protein level of RANTES (C) was in the range of 250 pg/mL and again TNF-α (D) levels were in low range. IL-1β (E), which showed no up- or down-regulation in microarray experiments, showed insignificant levels of protein in HBMEC culture supernatants. Data are presented as mean ± SD of duplicate experiments with 2 biologic replicates (n = 4).