Characterization of NKG2DL mAb and MICB ELISA. (A) C1R-MICA*01 (black histograms), C1R-MICB*02 (gray histograms), and C1R-neo (open histograms, solid line) were stained with BAMO1, AMO1, and BMO1 and an isotype control, respectively (open histograms, dotted line) and analyzed by flow cytometry (upper panel). C1R-ULBP1 (black histograms), C1R-ULBP2 (dark gray histograms), C1R-ULBP3 (light gray histograms), and C1R-neo (open histograms, solid line) were stained with AUMO1, BUMO2, CUMO2, and the respective isotype control (open histograms, dotted line; lower panel). (B) Standardization of the MICB sandwich ELISA. Serial dilutions of sMICB were analyzed in a sandwich of BAMO1 and BMO2 followed by detection with antimouse IgG2a-HRP. The means of 4 replicates including the respective SDs are shown. (C) Supernatants of CIR-neo and the respective MICA and MICB transfectants of C1R were investigated for levels of soluble MIC molecules by the MICA (▪) and MICB sandwich ELISA (▦). The means of duplicates with their SDs are depicted.