51results about How to "Less sample volume" patented technology

This invention provides devices, compositions and methods for determining the concentration of one or more metabolites or analytes in a biological sample, including cells, tissues, organs, organisms, and biological fluids. In particular, this invention provides materials, apparatuses, and methods for several non-invasive techniques for the determination of in vivo blood glucose concentration levels based upon the in vivo measurement of one or more biologically active molecules found in skin.

A method of detecting a collagen triple helix structure of by utilizing a bisulfide nano-material is disclosed. The method includes adding the bisulfide nano-material into a probe polypeptide solution to form a first system, adding the bisulfide nano-material into a mixture of a probe polypeptide solution and a polypeptide solution to be detected to form a second system, detecting fluorescence intensities of the first and second systems, and comparing the fluorescence intensities to determine whether a probe polypeptide and the polypeptide to be detected in the second system generate a collagen triple helix structure or not, wherein the concentration of the probe polypeptide in the first system is equal to the concentration of the probe polypeptide in the second system, and the probe polypeptide is a collagen polypeptide modified with a fluorescent molecule and having a specific sequence. The collagen triple helix structure can be accurately detected through the bisulfide nano-material in the method. The method has advantages of simple operation, a low cost, convenient detection, high sensitivity, high specificity, and a low sample using amount.

The present invention provides a method for ultrasensitive detection of dopamine based on nucleic acid aptamers. First, ssDNA1 is combined with dopamine aptamers and ssDNA2 through the principle of complementary base pairing to form double-stranded DNA1 with two 3' protruding ends, wherein , ssDNA2 has fewer bases than ssDNA1 and is complementary to ssDNA1, and the dopamine aptamer starts from the 3' end of ssDNA2 to partially complement ssDNA1; then add the sample to be tested, hairpin DNA, fluorescent dye SYBR GreenⅠ, and exonucleic acid Enzyme III, wherein, the number of bases of the hairpin DNA is less than that of ssDNA1 and can form a double-stranded DNA2 with a recess at the 3' end of the hairpin DNA chain with the free ssDNA1 through the principle of complementary base pairing. In the present invention, the dopamine aptamer recognizes dopamine, so that the aptamer is detached from the double-stranded DNA1, thereby continuously triggering the enzyme cutting reaction, reducing the fluorescence signal, and realizing the supersensitive detection of dopamine by using the cyclic amplification technology.

The invention discloses an analysis method for detecting furans compounds and pyrans compounds in beer, which combines a solid-phase extraction analysis method and a gas chromatogram / mass spectrometry analysis method. The analysis method comprises the following steps of preparation, solid-phase extraction, gas chromatogram / mass spectrometry analysis, detection and the like. The analysis method for detecting volatile furans compounds and pyrans compounds in beer is established and has the advantages of rapidness, small sample usage, accuracy, sensitiveness, high efficiency and the like. Small polystyrene / divinyl benzene columns selected in the solid-phase extraction process have the characteristics of strong adsorption capability, small organic solvent usage, convenience, safety, high efficiency and the like.

The invention relates to an online analysis method for hydrogen sulfide gas sulfur isotope in natural gas. The method includes the following steps: collecting natural gas samples; heating the oxidation furnace of the element analyzer to 1020°C; raising the temperature of the chromatographic column box to 50°C; introducing the reference gas into the stable isotope ratio mass spectrometer, and adjusting the mass-to-charge ratio to 66 The magnetic field at the center of the peak, and save the magnetic field value; connect the cylinder containing the natural gas sample to the sampling valve and put it into the fume hood, turn on the power of the fume hood; take the natural gas sample with an air-tight sampling needle; inject the natural gas sample into the In the sample port; the natural gas sample flows into the high-temperature oxidation tube with the carrier gas, and is oxidized into CO2, H2O, SO2 gas, and the mixed gas is carried by the carrier gas and flows through the dehydration tube to remove moisture; the mixed gas after removing moisture flows through the gas phase After the chromatographic column is separated, it enters the stable isotope ratio mass spectrometer through the continuous flow interface to measure the sulfur isotope composition and generate a spectrum to obtain the measurement result.