6 results about "Total internal reflection fluorescence microscope" patented technology

The application discloses a new method for quantitatively analyzing interface nucleic acid hybridization reaction and application thereof, and comprises the following steps: S1, constructing a DNA tetrahedron interface; S2, imaging the DNA tetrahedron interface through a total internal reflection fluorescence microscope; S3, realizing real-time monitoring of a hybridization event of the DNA tetrahedron interface by adopting double-color co-localization and analyzing a fluorescence signal; and S4, analyzing hybridization kinetics on the DNA tetrahedron interface by recording changes of the fluorescence signal with time. The application uses the DNA tetrahedron interface for single-molecule fluorescence imaging, can realize real-time monitoring of a single nucleic acid molecule hybridization event, improve detection sensitivity and specificity, accurately analyze kinetic parameters of a hybridization reaction, help realize more accurate performance evaluation of a nucleic acid sensor, has important significance for design and optimization of the nucleic acid sensor, and thus plays a greater role in the fields of clinical diagnosis, environmental monitoring and food safety.

The present invention concerns a portable total internal reflection fluorescence microscope (1) comprising: - a portable box (40) comprising: - a laser stage (10), comprising a laser (100), - an objective stage (30), comprising an objective (300), - a sample stage (20), comprising a sample (200) to be observed, wherein the sample stage (20) is disposed between the laser stage (10) and the objective stage (30), - a support (50) on the portable box (40), arranged for receiving a camera (21, 22), wherein the sample stage (20) comprises a prism (210), wherein the laser stage (10) is arranged such that the laser beam (110) has an incidence angle (θ) at the prism (210) comprised in the range of 75° to 90°, the incidence angle (θ) being the angle formed by the laser beam (110) at the prism (210) with respect to a normal (N) of a main plane of the sample stage (20), so as to have a total internal reflection of the laser beam (110) and thus detect a single fluorescent molecule in the sample (200).

This invention discloses a method for the separation and detection of exosomes in whole blood using a microfluidic chip. The method includes preparing a microfluidic chip with a specific structure for whole blood exosome separation and a PEGylated microfluidic chip with fishbone-like protrusions for capturing whole blood exosomes. Simultaneously, a viscoelastic solution is prepared and the whole blood sample is pretreated. The pretreated whole blood sample is injected into the microfluidic chip for whole blood exosome separation, and size-dependent separation of exosomes is achieved using a viscoelastic flow field. After concentration, a whole blood exosome concentrate is obtained. Exosomes are immobilized with paraformaldehyde, perforated, and biotinylated. After capture, a BODIPY polymer dot-coupled secondary antibody is prepared, combined with a primary antibody to complete exosome immunolabeling. After localization, multi-channel imaging using a total internal reflection fluorescence microscope is performed. This method achieves efficient separation and highly specific labeling detection of whole blood exosomes, improving the separation recovery rate and purity.

Disclosed is a diffractive optical element includes a substrate (BS) having a first surface and a second surface opposite the first surface, being transparent to light in at least one spectral range and having, in the spectral range, a refractive index that is greater than that of water, at least one metasurface able to diffract light radiation of wavelength λ within the spectral range, incident with an angle of incidence, according to a diffracted radiation, so that the diffracted radiation propagates in the substrate and reaches the second surface of the substrate at a diffracted angle θd that is greater than or equal to a limit angle (θc) of total internal reflection between the substrate and water, the metasurface being designed to have, for the angle of incidence, a transmission with a 0 order of diffraction below 5% and a transmission of the diffracted radiation corresponding to a −1 or +1 order of diffraction above 50%.

The invention relates to a single-molecule peptide recognition and enzyme activity detection method, in particular to a beta-secretase activity detection method based on fluorescent scintillation fingerprints and deep learning recognition. The method comprises the following steps: marking a spontaneous scintillation type fluorescent dye on a specific peptide substrate, and fixing the specific peptide substrate on the surface of a functionalized slide by utilizing click chemistry to realize stable anchoring of a single peptide molecule; then, a total internal reflection fluorescence microscope is adopted to collect a time sequence fluorescence track, and single molecule scintillation fingerprints before and after enzyme digestion are obtained. And track data is classified and analyzed by combining a deep learning model, so that whether the peptide molecules are subjected to enzyme digestion or not can be accurately judged, and quantitative detection of the enzyme activity is further realized. Compared with a traditional method, the method has the advantage that the detection sensitivity, the specificity and the adaptability to complex samples are remarkably improved. The beta-secretase is used as a model, the verification accuracy rate exceeds 88%, a new technical path is provided for enzyme activity analysis and early diagnosis of related diseases, and the method has a wide application prospect.

The invention relates to the technical field of microscopic imaging, in particular to a metasurface structure and a total internal reflection fluorescence microscope. The metasurface structure is applied to the total internal reflection fluorescence microscope, the total internal reflection fluorescence microscope comprises a microscope objective, the metasurface structure comprises a silicon dioxide substrate, silicon columns and a coating material layer, and the silicon columns are arranged on the silicon dioxide substrate in an array distribution mode; the coating material layer covers the surfaces of the silicon column and the silicon dioxide substrate, and the metasurface structure can reflect fluorescence signals with wavelengths in a preset range to a microscope objective and transmit laser or fluorescence signals with other wavelengths. The metasurface structure provided by the embodiment of the invention can reflect the fluorescence signal with the wavelength in the preset range to the microscope objective and transmit the laser or fluorescence signal with other wavelengths, so that the fluorescence signal with the wavelength in the preset range can enter the microscope objective, and the detection sensitivity of the total internal reflection fluorescence microscope is enhanced.