Dual-label one-step immunoassay for simultaneous measurement of free and total prostate-specific antigen concentrations and ratios in serum
We developed a simple one-step dual-label immunoassay for simultaneous measurement of the free, noncomplexed form of prostate-specific antigen (PSA) and total PSA. The assay is based on time-resolved fluorescence and includes a stable fluorescent chelate of Eu to label a monoclonal antibody (mAb) that detects only free PSA, whereas a second mAb labeled with a fluorescent chelate of Tb provides equ