Determination of the platelet-derived growth factor BB by sandwich format thrombin-linked aptamer assay on microplate

Microplate based assays have advantages such as rapid detection and high throughput analysis. Here, we reported a thrombin linked aptamer assay (TLAA) on a microplate in sandwich format for the detection of platelet-derived growth factor BB (PDGF-BB) using thrombin as the enzyme label. In our assay, the target protein PDGF-BB was captured by anti-PDGF-BB antibody coated on the microplate and sandwiched with a DNA probe containing an anti-PDGF-BB aptamer sequence and anti-thrombin aptamer sequence. Thrombin was labeled on the sandwich complex through aptamer–thrombin interaction. Finally, the thrombin catalyzed the conversion of the substrate to a detectable product, generating signals for final PDGF-BB detection. The sandwich format of the TLAA on a microplate allowed the selective detection of PDGF-BB with a detection limit of 0.25 nM.