70 results about "Direct assay" patented technology

A direct assay is described using novel three-dimensional polymeric assemblies which change from a blue to red color when exposed to an analyte, in one case a flu virus. The assemblies are typically in the form of liposomes which can be maintained in a suspension, and show great intensity in their color changes. Their method of production is also described.

The invention provides enzymatic methods for direct determination of percentage of glycated hemoglobin in blood samples without the need of a separated measurement of total hemoglobin content in blood samples. The methods utilizes one or two different types of oxidizing agents which selectively oxidize low-molecular weight reducing substances and high-molecular weight (mainly hemoglobin) reducing substances in blood samples, coupled with enzymatic reactions catalyzed by proteases, fructosyl amino acid oxidase. The amount of hydrogen peroxide generated in the reaction is measured for determination of percentage of glycated hemoglobin in blood samples. The invention provides kits for performing the methods of the invention.

The invention relates to an analysis method for quickly detecting urine creatinine by isotopic dilution, extractive electrospray ionization (EESI) and tandem mass spectrometry (MS/MS), and belongs to an analysis and detection means for a renal function biomarker. The method is characterized in that the detection means is that an EESI source is subjected to direct MS and MS/MS under normal pressure, linear trap quadrupole (LTQ)-MS/MS is set to be in a positive ion detection mode, the parameters of the EESI source, such as the composition of an electrospray solvent are adjusted, an isotopic dilution technology and a standard addition method are adopted in quantitative analysis, creatinine at gradient concentration and deuterated creatinine at fixed concentration are added into an urine sample, direct analysis is performed, a standard addition curve is drawn, and the concentration of the urine creatinine is obtained. The urine creatinine can be directly measured under the condition that the sample is not pretreated, and the defects of a long analysis period and low efficiency in the prior art are overcome. The method has the characteristics of quickness, accuracy, capability of resisting interference from a substrate, and the like, and is particularly suitable for the clinical research of renal disease (such as the early diagnosis of acute renal failure) and high-flux sample analysis.

Skin cholesterol is measured by applying an adhesive tape onto a selected area of the skin to adhere the tape to the selected skin area and stripping the tape off the selected skin area to obtain a sample representative of the outer stratum corneum layer of the skin, the sample adhering to the tape so as to have exposed skin constituents. The sample is assayed using a detector reagent that specifically binds to cholesterol and in addition has an indicator component that allows quantitation of the amount of cholesterol present in the exposed skin constituents.

Particle-based methods, compositions, and kits are provided for the detection of the free form of a member of a binding pair which may be found free or in a bound state in a sample. Inhibition and direct assay formats are provided. In one embodiment, the invention provides diagnostic tools for the diagnosis of thrombophilia through the detection of free protein S.

The invention discloses a method for quickly measuring ethyl carbamate in liquor samples in batches, and belongs to the technical field of analytical chemistry and food safety detection. The method comprises the following steps: firstly, pretreating the liquor samples with a EC (ethyl carbamate) special solid phase column to extract EC in the liquor samples; then adding EC degrading enzyme into a solution system obtained by extraction; finally, adding sodium pyruvate and NADH which serve as matrixes into a detection system, adjusting the pH with a buffer solution, performing electrochemical detection by utilizing an AlaDH-modified silk-screen printing electrode, and measuring a linear relation between a current response value drop caused by consumption of the NADH and the concentration of the EC with a current-time method, thus measuring the EC content. According to the method, an EC sensor based on the enzyme-modified silk-screen printing electrode is built and is linked with the special solid phase column for EC extraction, so that influence of urea which is a main interfering substance in a liquor matrix is effectively eliminated, and direct measurement of the EC content of each liquor sample such as yellow wine is realized. Compared with a GC-MS (Gas Chromatography-Mass Spectrometer) serving as a principal method for EC measurement at the present, the method disclosed by the invention has the advantages that no large-sized instrument equipment is needed, and fast, high-sensitivity and low-cost batch measurement can be realized.

The present invention is directed to a kit and a method for a fast and direct determination of the coagulation potential of a sample of blood or plasma utilising a thrombin substrate. The kit comprises at least one activator of the plasmatic substrate with a K_M preferably coagulation system and a thrombin less than or equal to 200 μM in a relatively low concentration with respect to the sample whereby the substrate is wholly consumed within 5 to 600 seconds. Observations are made leading to a determination of the maximum rate of substrate consumption.

The invention discloses a method for quickly determining trace osmium in nickel alloy by inductively coupled plasma mass spectrometry. By adding a reducing agent ascorbic acid into the solution to be tested, the high-valence osmium (+8) is reduced, and the valence of the osmium standard solution is The state is consistent, so that the atomization efficiency in ICP-MS is consistent, and the standard curve method is used to directly measure the amount of osmium in the nickel alloy test solution on the inductively coupled plasma mass spectrometer. Other coexisting elements in the nickel alloy will not be Restored to solid form and precipitated. The sample does not need to be absorbed by distillation to determine the amount of osmium by ICP-MS; it does not depend on the addition of isotope diluent while processing the sample ¹⁹⁰ Os, make it fully mixed with the sample or standard solution, exchange to reach equilibrium, keep the same chemical form of osmium, and then use the ICP-MS method to determine the amount of osmium. The method can accurately and quickly measure the trace osmium in the nickel alloy material rich in platinum group metals by using the method. The method is simple, fast and has high accuracy and meets the analysis requirements of the trace osmium in the nickel alloy.

The invention relates to a method of directly detecting content of mercury in solid rubber by means of a mercury detector. The method includes steps of: setting working conditions of the mercury detector as follows: drying temperature is 350 DEG C, drying time is 30 s, purging time is 30 s, analysis time is 12 s, reading time is 24 s, and oxygen pressure is 0.45 MPa; sample weight of a rubber sample is 0.03-0.15 g to the accuracy of 0.1 mg, sample decomposition time is 1-4 min, and sample decomposition temperature is 550-750 DEG C; then clicking start to detect the sample; after the detectionis finished, reading the detection result of content of mercury in the solid rubber. The method is high in detection speed and is free of pretreatment of the sample, allows direct detection and has simple operation, can avoid volatilization loss during sample treatment and guarantee accuracy of the results, can reduce damage on environment and body health, and is suitable for large-scale analysison the smaple and direct detection of a solid sample of a complex substrate, and has extensive application prospect.

The invention discloses a hand-foot-mouth disease virus EV71 nucleic acid detection kit, and belongs to the technical field of virus detection. The kit consists of N.BstNBI enzyme, T7 RNA (Ribonucleic Acid) polymerase, AMV (Avian Myeloblastosis Virus) reverse transcriptase, RNase H, NASBA (Nucleic Acid Sequence Based Amplification) reaction solution, a NASBA reaction primer, an RIDA (Radioisotope Dilution Assay) probe, DEPC (Diethypyrocarbonate) water, influenza virus a HINI RNA, breast cancer cell MCF-7 total RNA and EV71 RNA. According to the kit, a hand-foot-mouth disease virus EV71 nucleic acid sequence is detected by combining NASBA and RIDA technologies; and the kit has the advantages of sensitivity, specificity, easiness, convenience, high speed, high efficiency, no dependency on special instruments and the like.

The invention discloses a method for extracting salinomycin compounds from an animal sample and a special immunoaffinity absorbent thereof. The immunoaffinity absorbent for extracting the salinomycin compounds from the animal sample consists of a solid phase carrier and a salinomycin monoclonal antibody which is coupled with the solid phase carrier; the salinomycin monoclonal antibody is an antibody obtained by taking a conjugate of salinomycin semiantigen and carrier protein as immunogen; and the salinomycin compounds are salinomycin or methylsalinomycin. The immunoaffinity absorbent and a chromatographic column use the high specific salinomycin monoclonal antibody, have high selectivity, ensure the reliability of detection effect, greatly simplify the pretreatment processes of samples at the same time, are particularly applicable to the pretreatment of a trace amount of salinomycin and methylsalinomycin in muscle and liver, and improve the analysis quality. A detection method of the invention can efficiently detect the content of the salinomycin and the methylsalinomycin, and remedy the disadvantages that the direct assay of the samples by a single immunoassay technology has less information amount, poor quantification accuracy, or low selectivity of physical and chemical methods and so on, so the immunoaffinity absorbent, the chromatographic column, a reagent kit and the methods for extracting and detecting the salinomycin compounds in the animal sample are suitable to be promoted and applied.

The invention discloses a printing ink volatility detector. The detector comprises a box body, a liquid storage cavity is formed in the box body , printing oil can be stored in the liquid storage cavity for detection, and a gas adjusting mechanism is also arranged in the liquid storage cavity and can pump out air in the liquid storage cavity by an air pump. A fixed period is limited, and the hydraulic pressure of the printing ink liquid indirectly reflect the volatilized mass of the ink within the period, and further the volatile degree of the ink is reflected; gas components and content of the printing oil are sampled and detected, and the volatility of the ink can be directly measured; and direct and indirect detection methods enable a more accurate detection result.

The invention relates to a method for testing transfer volumes of specific volatile and semi-volatile organic matters in paper and a paperboard, belongs to the technical field of analytic chemistry, and particularly relates to the method for directly testing transferred volatile and semi-volatile compounds by taking Tenax as the simulant by virtue of a headspace gas chromatography-mass spectrometry (HS-GC/MS). The method comprises the following steps: (1) preparing a simulation sample, assembling, and covering the surface of a to-be-tested object with the Tenax; (2) simulating the assembled sample in a normal drying oven under a temperature testing condition for required time; (3) directly analyzing a simulant by virtue of the HS-GC/MS, so as to obtain the transfer volumes. The method can be used for effectively testing the transfer volumes of the specific volatile and semi-volatile organic matters in the paper and the paperboard, is feasible, easy to operate, accurate and sensitive and has popularization and application values.

The invention discloses a method for detecting bisphenol A (BPA). The method employs pre-column derivative-high performance liquid chromatography (HPLC) for detection. The method comprises the following steps of: using an aniline compound as a derivatization reagent to react with bisphenol A to generate a diazo compound; and analyzing derivatized product by HPLC to obtain the BPA content in a sample. The principle is that the BPA has stronger ultraviolet or fluorescence absorption after reacting with the derivatization reagent to generate the diazo compound, so as to reduce the detection limitand improve the sensitivity. The method has the advantages of low detection limit, high sensitivity, and simple operation, and capable of accurately quantitatively detecting the BPA in the sample. The detection limit of the method is 0.18ng, and the quantitative limit is 0.54ng. The detection limit is lower compared to the HPLC direct assay. The method disclosed by the invention can be used in the field of food safety detection, such as a food packaging material and a limit check of BPA in food.

The invention relates to the technical field of lead-based alloy detection, and in particular relates to a method for determining the content of non-metallic elements in crude lead. The content of non-metallic elements in crude lead is directly related to lead-containing slag of crude lead. The invention mainly solves the problems of poor detection precision caused by extensive crude lead slag-containing determination modes and non-uniform determination standards, and easy divergence of detection results during multi-party detection. The determination method comprises two times of lead contentdetection, namely direct reading spectrometer detection and EDTA titration method detection, on electrolytic lead and crude lead, and the content of non-metallic elements is calculated by analyzing the difference value of the two times of detection, so that the lead slag content of the crude lead is represented. According to the method provided by the invention, the non-metallic element content which is difficult to directly measure is indirectly calculated through two detection methods with different principles, and the method has the advantages of simple principle and high detection precision.

The invention discloses a near-infrared online quality detection method for rehmannia. The method comprises the steps of (1) conducting sample preparation, specifically, taking rehmannia decoction piece samples from different producing areas and different batches; (2) simultaneously collecting and recording a near infrared spectrogram of the rehmannia sample and a near infrared spectrogram of the ground rehmannia; (3) preprocessing the spectral data, specifically, respectively adopting an original spectrum, first-order derivation, second-order derivation, multivariate scatter correction, vector normalization, convolution smoothing filtering, multivariate scatter correction + vector normalization, convolution smoothing filtering + multivariate scatter correction, convolution smoothing filtering + vector normalization, preprocessing the near infrared spectrum data of the rehmannia sample before and after grinding; and (4) carrying out model screening by adopting a convolutional neural network, PLSR and segmented PLSR, and establishing a rehmanniae quantitative correction model. The established model is accurate and reliable, the operation is rapid and simple, and the content of catalpol and moisture in the rehmannia decoction pieces can be directly measured in a lossless manner.