Abstract: The present invention discloses the application of aptamer in recognition and binding of alkaline phosphatase heterodimer. The present invention provides an aptamer or its derivative, the nucleotide sequence of which is shown in SEQ ID NO: 1 in the sequence listing. The present invention also provides a kit including an aptamer or a derivative thereof, and a carrier for fixing or coupling the aptamer or a derivative thereof, wherein the aptamer is a single-stranded DNA molecule having the nucleotide sequence as shown in SEQ ID NO: 1. The method for capturing and detecting circulating tumor cells, exosomes and free alkaline phosphatase in peripheral blood highly expressing alkaline phosphatase based on the aptamer magnetic nanoparticle technology of the present invention can achieve highly selective capture and detection of target cells, exosomes or free proteins.

Abstract: In this invention, a biomarker discovery method has been developed using specific biotin-labeled oligonucleotide ligands and magnetic streptavidin beads. In one embodiment, the oligonucleotide ligands are firstly generated by whole-cell based SELEX technique. Such ligands can recognize target cells with high affinity and specificity and can distinguish cells that are closely related to target cells even in patient samples. The targets of these oligonucleotide ligands are significant biomarkers for certain cells. These important biomarkers can be captured by forming complexes with biotin-labeled oligonucleotide ligands and collecting the complexes using magnetic streptavidin beads, whereupon the captured biomarkers are analyzed to identify the biomarkers. Analysis of biomarkers include HPLC-Mass Spectroscopy analysis, polyacrylamide gel electrophoresis, flow cytometry, and the like. The identified biomarkers can be used for pathological diagnosis and therapeutic applications.

Abstract: A system and method for producing an oligonucleotide having a high affinity for extracellular or cell surface markers on a target cell. The resultant oligonucleotide probe can be used to detect a target biomolecule, in particular a cancer cell or infectious agent such as a bacterium, virus, or fungus, comprising an aptamer having a high affinity for the biomolecule, wherein at least one labeled dye is attached to the aptamer. The labeled dye causes the aptamer to emit a baseline, non-visible emission. When the aptamer (also referred to herein as a probe) of the invention interacts with a target biomolecule, the fluorescence emission changes from the baseline emission to an emission that is visually detectable.

Abstract: In this invention, a biomarker discovery method has been developed using specific biotin-labeled oligonucleotide ligands and magnetic streptavidin beads. In one embodiment, the oligonucleotide ligands are firstly generated by whole-cell based SELEX technique. Such ligands can recognize target cells with high affinity and specificity and can distinguish cells that are closely related to target cells even in patient samples. The targets of these oligonucleotide ligands are significant biomarkers for certain cells. These important biomarkers can be captured by forming complexes with biotin-labeled oligonucleotide ligands and collecting the complexes using magnetic streptavidin beads, whereupon the captured biomarkers are analyzed to identify the biomarkers. Analysis of biomarkers include HPLC-Mass Spectroscopy analysis, polyacrylamide gel electrophoresis, flow cytometry, and the like. The identified biomarkers can be used for pathological diagnosis and therapeutic applications.