Fig. 6. Investigation of the specificity of TdT-FCI by using PSA-specific monoclonal antibodies. All of the antigens used in this study are 500 pg mL^–1 and the fluorescence response of PSA is normalized to be 1. (Inset) The corresponding FCM fluorescence histograms of the MBs treated with different kinds of antigens by using PSA-specific antibodies.