Bioluminescent aptamer-based solid-phase microassay to detect lung tumor cells in plasma

Abstract Two high-affinity DNA aptamers for lung tumor cells were applied as biospecific elements in bioluminescent assay of patient blood. The oligonucleotide complementary to the 5′ end of both aptamers carrying either biotin or Ca 2+ -regulated photoprotein obelin was used to form a sandwich-type analytical complex on the surfaces of magnetic streptavidin-activated microspherical particles. Clinical blood samples from cases of morphologically confirmed lung cancer and control samples were analyzed applying the developed assay. From the receiver operator curve (ROC) analysis, the chosen threshold value as clinical decision limit offers the sensitivity of 91.5% and the specificity of 75% (p