Binding Assays Utilizing Time-Resolved Up-Converting Luminescence Detection
OwnerAimin Heinventor
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Abstract
This invention describes a general binding assay method to detect the presence and quantity of analyte in a sample. The method uses time-resolved up-converting fluorescence detection technique to provide highly sensitive detection without using expensive optical components such as band-pass optical filters. The method uses pulsed long wavelength light for excitation and time-delayed luminescence detection, resulting in little interferences from sample matrices. Furthermore, the usage of long wavelength excitation light requires simpler sample preparation and processing such as removal of red blood cells, which otherwise will significantly interfere with excitation efficiency of the luminescence probes.
Claims23
A binding assay method for detecting the presence or quantity of an analyte in a sample, the assay method comprising:
- a. Contacting a liquid sample containing the analyte with a first specific binding member immobilized on the surface of a solid substrate and a second specific binding member tagged with a detection probe, wherein the detection probe is capable of emitting luminescence at a shorter wavelength than the wavelength of an excitation light with a luminescence lifetime of more than 5 μsec wherein the first specific binding member and second specific binding members bind different epitopes of the analyte to form a sandwich complex;
- b. Removing the components in the mixed sample that are not bound to the surface and washing away those loosely bounded components on the surfaces using washing solutions;
- c. Exciting the detection probes captured on the surface through the analyte using pulsed illumination at a first wavelength to obtain a detection signal by collecting and measuring the luminescence at a second wavelength after a certain period of time has elapsed following each pulse, wherein the second wavelength is shorter than the first wavelength;
- d. Comparing the detection signal with a calibration curve to obtain the amount of analyte in the sample, wherein the detection signal is proportional to the detection signal.
A binding assay method for detecting the presence or quantity of an analyte in a sample comprising:
- a. Contacting a sample containing the analyte with a first specific binding member immobilized on the surface of a solid substrate and a known amount of analyte or analyte analog tagged with a detection probe, wherein the detection probe is capable of emitting luminescence at a shorter wavelength than the wavelength of an excitation light with a luminescence lifetime of more than 5 μsec wherein the first specific binding member bind specifically the analyte or analyte analog to form a complex;
- b. Removing the components in the mixed sample that are not bound to the surface and washing away those loosely bounded components on the surfaces using washing solutions;
- c. Exciting the detection probes captured on the surfaces using pulsed illumination at a first wavelength to obtain a detection signal by collecting and measuring the luminescence at a second wavelength after a certain period of time has elapsed following each pulse, wherein the second wavelength is shorter than the first wavelength.
- d. Comparing the detection signal with a calibration curve to obtain the amount of analyte in the sample, wherein the detection signal is reversely proportional to the detection signal.
Dependencies are inferred from the claim text.