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1.
Daidzin, genistin, and glycitein are major isoflavone compounds in soybean that are indispensable nutrients in traditional Chinese foods. Generally, strategies for detecting and separating soy isoflavones have been based on HPLC and chromatographic techniques, which are tedious and time‐consuming procedures. In the present study, we developed an ELISA‐based approach for daidzin detection using a broad‐specificity monoclonal antibody (clone number: AA9) with an effective detection range of 10–10 000 ng/mL. Subsequently, we prepared an immunoaffinity column by coupling the monoclonal antibody AA9 to CNBr‐activated Sepharose 4B. Our results demonstrate that the immunoaffinity column can efficiently and specifically extract daidzin, glycitein, and genistin from numerous structurally similar soy isoflavones in leguminous plants, thereby providing a new method for the extraction of target components from similar compounds in natural products.  相似文献   

2.
In this work, a new monoclonal antibody specific for glycyrrhizic acid was prepared and characterized. A hybridoma secreting an anti‐glycyrrhizic acid monoclonal antibody was produced by fusing splenocytes from a mouse immunized against a glycyrrhizic acid–bovine serum albumin conjugate with the hypoxanthine–aminopterin–thymidine‐sensitive mouse myeloma cell line (Sp2/0‐Ag14). Subsequently, an indirect, competitive enzyme‐linked immunosorbent assay for glycyrrhizic acid was developed using the monoclonal antibody. In this assay, we detected an effective measuring range of 78.12–2500 ng/mL. Both intra‐assay and inter‐assay repeatability and precision were achieved, with relative standard deviations lower than 10%. In addition, glycyrrhizic acid levels in both formulated Chinese medicines and biological samples were determined with high sensitivity and efficiency. We then successfully developed a reliable immunoaffinity chromatography to separate glycyrrhizic acid completely from its parent medicine. These methods will contribute to further research investigations to better understand the interactions of glycyrrhizic acid with other drugs in the complex system of traditional Chinese medicine.  相似文献   

3.
Summary The BIAcoreTM Biosensor System utilizes a detection principle known as Surface Plasmon Resonance (SPR) which, in simple terms, detects changes in the refractive index of a solution in contact with a gold film. The gold film is surface modified with carboxymethylated dextran to produce a hydrophillic matrix onto which macromolecules may be covalently immobilized. In this respect, the BIAcoreTM is similar to any other insoluble matrix, such as a chromatographic support. The SPR detection principle, however, allows one to directly visualize the interaction under study, in real time and without the need for reporter molecules such as enzyme-labels. In addition, the very small sample requirements, automated robotics unit and ease of data analysis suggest the potential use of the BIAcoreTM instrumentation for assay development and possibly process development, especially where bio-specific interactions such as immunoaffinity chromatography are used as a step in the process. In this report, we demonstrate the use of the BIAcoreTM SPR detector for the micro-scale determination of conditions for immunoaffinity chromatography of soluble complementreceptor 1, sCR1.  相似文献   

4.
Yuwei Qiao  Bin Wang  Anping Deng 《Talanta》2009,80(1):98-5161
The preparation and characterization of an immunoaffinity chromatography (IAC) column for the specific extraction and enrichment of trace contraceptive drug levonorgestrel (LNG) from water samples were described. The IAC column was constructed by covalently coupling specific polyclonal antibody against LNG to CNBr-activated Sepharose 4B and packed into a common solid phase extraction (SPE) cartridge. The extraction conditions including loading, washing and eluting solutions, as well as the effect of flow rate on the extraction were carefully optimized. Pure water, 5% of methanol and 50% of methanol were respectively selected as loading, washing and eluting solutions, while the flow rates in the loading, washing and eluting steps were selected to be 1.0, 2.0 and 0.5 mL min−1, respectively. Under optimal conditions, the IAC column was characterized in terms of maximum capacity, extraction recovery and stability. It was found that, for IAC column packed with 0.2 g of solid support immobilized with antibody, the maximum capacity for LNG was about 260 ng. The extraction recoveries of the column for LNG at three different spiked concentrations were within 95.3-106.9%. After more than 35 times repeated usage, there was not significant loss of specific recognition. Using high performance liquid chromatography (HPLC) as an analytical tool, trace amount of LNG in the range of ng L−1 was found in river water and wastewater samples after 600-fold enrichment, demonstrated the feasibility of the prepared IAC column for LNG extraction.  相似文献   

5.
A rabbit antibody immunoaffinity (IA) column procedure was evaluated as a cleanup method for the determination of atrazine in soil, sediment, and food. Four IA columns were prepared by immobilizing a polyclonal rabbit anti-atrazine antibody solution to HiTrap Sepharose columns. Atrazine was bound to the IA columns when the loading solvents were either 100% water, 2% acetonitrile in water, or 10% methanol in phosphate buffered saline (PBS). Quantitative removal of atrazine from the IA columns was achieved with elution solvents of either 70% ethanol in water, 70% methanol in water, or 100% methanol. One control column was prepared using nonspecific rabbit IgG antibody. This control column did not retain any applied atrazine indicating atrazine did not bind indiscriminately to protein or the Sepharose support. The four IA columns showed reproducible coupling efficiency for the immobilization of the atrazine antibody and consistent binding and releasing of atrazine. The coupling efficiency (4.25 mg of antibody in 1 mL of resin bed) for the four IA columns ranged from 93 to 97% with an average of 96 ± 2% (2.1%). Recoveries of the 500, 50, and 5 ng mL−1 atrazine standard solutions from the four IA columns were 107 ± 7% (6.5%), 122 ± 14% (12%), and 114 ± 9% (8.0%) respectively, based on enzyme-linked immunosorbent assay (ELISA) data. The maximum loading was approximately 700 ng of atrazine for each IA column (∼0.16 μg of atrazine per mg of antibody). The IA columns could withstand 100% methanol as the elution solvent and could be reused more than 50 times with no change in performance. The IA columns were challenged with soil, sediment, and duplicate-diet food samples and effectively removed interferences from these various matrices for subsequent gas chromatography/mass spectrometry (GC/MS) or ELISA analysis. The log-transformed ELISA and GC/MS data were significantly correlated for soil, sediment and food samples although the ELISA values were slightly higher than those obtained by GC/MS. The IA column cleanup procedure coupled with ELISA analysis could be used as an alternative effective analytical method for the determination of atrazine in complex sample media such as soil, sediment, and food samples.  相似文献   

6.
Li Y  Wang Y  Yang H  Gao Y  Zhao H  Deng A 《Journal of chromatography. A》2010,1217(50):7840-7847
The establishment of an immunoaffinity chromatography (IAC) for simultaneously selective extraction of four illegal colorants Sudan dyes (Sudan I, II, II and IV) from food samples was described. The IAC column was constructed by covalently coupling monoclonal antibody (mAb) against Sudan I to CNBr-activated Sepharose 4B and packed into a common solid phase extraction (SPE) cartridge. It was observed that IAC column was able to separately capture Sudan I, II, III and IV with maximum capacity of 295, 156, 184 and 173ng, respectively. The extraction conditions including loading, washing and eluting solutions were carefully optimized. Under optimal conditions, the extraction recoveries of the IAC column for Sudan I-IV at two different spiked concentrations were within 95.3-106.9%. After 50 times repeated usage, 64% of the maximum capacity was still remained. Six food samples randomly collected from local supermarket without spiking Sudan dyes were extracted with IAC column and detected by high performance liquid chromatography (HPLC). It was found that there was no detectable Sudan II, III and IV in all six food samples, but Sudan I with the content of 2.7-134.5ngg(-1) was detected in three food samples. To further verify the extraction efficiency, other three negative samples were spiked with Sudan I-IV at the concentrations of 20ngg(-1) and 50ngg(-1), which were then extracted with IAC column. The extraction recoveries and relative standard deviation (RSD) were 68.6-96.0% and 4.8-15.2%, respectively, demonstrating the feasibility of the prepared IAC column for Sudan dyes extraction.  相似文献   

7.
This study presents two simple and rapid methods for the quantification of therapeutic mAbs based on LC. Two mAbs (bevacizumab and infliximab) in plasma samples were purified using magnetic beads immobilized with a commercially-available idiotype antibody for each mAb. Purified mAbs were separated with HT-RPLC and detected with their native fluorescence. Using immunoaffinity beads, each mAb was selectively purified and detected as a single peak in the chromatogram. The HT-RPLC achieved good separation for the mAbs with sharp peaks within 20 min. The calibration curves of the two mAbs ranged from 1 to 20 μg mL−1 (bevacizumab) and 1–10 μg mL−1 (infliximab), and they had strong correlation coefficients (r2 > 0.998). The LOD of bevacizumab and infliximab was 0.07 and 0.15 μg mL−1, and the LLOQ of bevacizumab and infliximab was 0.12 and 0.25 μg mL−1, respectively. Thus, the sensitivities were sufficient for clinical analysis. Immunoaffinity purification with HT-RPLC produced a selective and accurate bioanalysis without an LC-MS/MS instrument. Both methods could become general-purpose analytical methods and complement the results obtained with conventional LBA.  相似文献   

8.
通过碳二亚胺法将吡虫啉交联于牛血清蛋白(BSA)作为免疫抗原,混合酸酐法将吡虫啉交联于卵清蛋白(OVA)作为包被抗原,免疫Balb/c小鼠,采用B细胞杂交瘤技术,经免疫、融合、筛选、克隆,得到抗吡虫啉单克隆抗体,抗体亚类为IgG1,制备的单克隆抗体效价达1×107,确定了吡虫啉酶联免疫吸附分析方法(ELISA)的最佳工作条件,建立了定量测定吡虫啉的间接竞争ELISA方法。本方法的IC50为(15.12±1.28)μg/L,检出限为(1.76±0.02)μg/L。与其它吡虫啉结构类似物无交叉反应。批内相对标准偏差为4.5%;批间相对标准偏差5.1%,饮用水、重庆理工大学地下水和重庆市花溪河地表水平均添加回收率分别为102%,97%和85%。本研究建立了一种快速检测环境水中吡虫啉残留的方法。  相似文献   

9.
Pyraclostrobin belongs to a new generation of fungicides widely used to preserve high valuable crops. In the present study, three monoclonal antibodies with different affinities to this modern strobilurin have been evaluated for their usefulness in the production of immunoaffinity columns suitable for the solid-phase extraction, concentration, and clean-up of residues from food commodities. Different immunosorbents were produced and characterized in terms of antibody immobilization efficiency, immunosorbent binding capacity, optimum elution conditions, and reusability. Covalent coupling of the antibodies to Sepharose-CNBr gel took place with high yield (over 90%), whereas the immunosorbent efficacy to retain the analyte (from 28 to 68%) was shown to depend on the amount and type of antibody immobilized on the support. As a matter of fact, columns prepared with the monoclonal antibody PYs5#14 were able to selectively bound up to 53 μg of pyraclostrobin per gram of beads. Acetonitrile solutions were preferred over methanolic ones for analyte elution, and some immunosorbents could be reused at least 4-6 times provided that the amount of pyraclostrobin and the volume of sample did not overload the column. Effectiveness of the selected immunoaffinity column was evidenced by the development of an extraction procedure for pyraclostrobin residues from fruit juices and further determination by high-performance liquid chromatography with UV detection. A concentration factor of 50 times was achieved with the developed immunoaffinity column, which eventually resulted in a limit of quantification of 0.01 mg L(-1). Finally, quantitative recoveries were obtained on apple juice and red grape must samples spiked with pyraclostrobin from 0.01 to 1 mg L(-1).  相似文献   

10.
Matrix interference and contamination from analytical procedures are two major issues in the detection of trace level of bisphenol A (BPA) in environmental water. In this paper, we report a highly selective and efficient method for on-line extraction of BPA from water samples followed by quantification with liquid chromatography–electrospray ionization tandem mass spectrometry (LC–ESI/MS/MS). Poly(ethylene dimethacrylate-glycidyl methacrylate) monolith was synthesized in 50 mm × 4.6 mm i.d. stainless steel cartridges and the epoxy-groups on the surface of the monolith were hydrolyzed and oxidized to aldehyde functions. Antibodies against BPA were covalently immobilized onto the monolithic column via Schiff base reaction. The optimum application buffer and elution buffer were found to be pH 5.5 phosphate buffered saline (PBS) and methanol–water (70:30, v/v), respectively. The obtained immunoaffinity monolithic columns were on-line coupled to LC–MS/MS using column-switching valves and the system was applied to analyze BPA in real environmental water samples. The method achieved a detection limit of 0.3 ng L−1 using a sample volume of 100 mL. The linear calibration range was 1.0–160 ng L−1. Samples including tap water, lake water and effluent from municipal sewage treatment plant were all measured with satisfactory results.  相似文献   

11.
A simple and fast immunoaffinity method is proposed for the determination of gliadins for the first time using gold nanoparticles (AuNPs) as labels. The tracer used consists in a gliadin-AuNP conjugate prepared by the adsorption of gliadins onto the nanoparticle surface. Two AuNP sizes with diameters of 10 nm and 20 nm were assayed to compare the behaviour of the corresponding tracer in the assay. The method relies on the injection in a commercial Protein G column of a preincubated mixture containing gliadins, polyclonal anti-gliadin antibodies, and the gliadin-AuNP tracer. This approach allows the separation of free and bound tracer fractions without any additional elution step, and the direct measurement of the resonance light scattering intensity of the free tracer through the peak height of the immunochromatogram, which is proportional to the analyte concentration. The immunocolumn can be used up to 25 times without eluting and it can be regenerated for at least 20 times. The dynamic ranges of the calibration graphs and the detection limits are 0.5-15.0 and 1.5-15.0 μg mL−1 gliadins, and 0.2 μg mL−1 and 0.8 μg mL−1 gliadins, using 20-nm and 10-nm Au-NPs as labels, respectively. The precision, expressed as relative standard deviation, ranges between 2.7% and 2.9% using 20-nm AuNPs and 4% and 6.1% for 10-nm AuNPs. The method has been applied to the determination of the prolamin fraction in beer samples, obtaining recovery values in the range 71.2% and 101.7%.  相似文献   

12.
通过化学修饰合成了噻虫嗪人工半抗原,采用碳二亚胺法将该半抗原与牛血清蛋白(BSA)和卵清蛋白(OVA)偶联,成功制备了分子结合比合理的免疫原和包被原。经过免疫原免疫6周龄Balb/c小鼠、PEG介导免疫鼠脾细胞和骨髓瘤细胞的融合和阳性杂交瘤细胞的筛选和克隆化,获得了效价高达1∶6.4×105的抗噻虫嗪单克隆抗体,抗体亚类为IgG1型。优化了ELISA实验条件,建立了基于单克隆抗体技术的噻虫嗪残留间接竞争ELISA方法。本方法的抑制中浓度(IC50)为0.0255mg/L,检测灵敏度(IC20)为0.0022mg/L,检出限(IC10)为0.001mg/L。除噻虫胺外,该抗体与其它噻虫嗪结构类似物无交叉反应。以自来水为基质的噻虫嗪添加回收实验显示,0.01,0.5和10.0mg/L添加水平的回收率均大于75%,且各添加水平重复测定8次的相对标准偏差均小于8%,说明所建立的间接竞争ELISA准确度高,重复性好,适合水中噻虫嗪残留的检测。  相似文献   

13.
Polyclonal antibodies against microcystin-LR (MC-LR), a cyclic heptapeptide toxin, were generated in rabbits using MC-LR-BSA. An enzyme-linked immunosorbent assay (ELISA) was developed for the characterization of the antibodies and their potential use for analytical purposes. The concentration of MC-LR that inhibits 50% of antibody-antigen binding (IC50) was 0.5 μg L−1 for the indirect ELISA format and 0.9 μg L−1 for the direct ELISA, using MC-LR-horseradish peroxidase conjugate. The limit of detection corresponding to IC80 was found to be 0.06 μg L−1, well below the Word Health Organization level for drinking water of 1 μg L−1. The direct competitive ELISA was applied to water samples and was shown useful for screening purposes. The developed anti-microcystin antibodies were immobilized on solid supports for use in selective solid phase extraction (SPE) systems, prior to liquid chromatography (LC) quantification. An immunoaffinity cartridge (IAC), a Sepharose®-based cartridge incorporating 2 mg of antibodies allowed the selective and quantitative recovery of a mixture of 0.2 μg of MCs showing potential use in sample preparation of real matrices. When applied to water and green algae samples, average recoveries from Sepharose®-based cartridges were in the range of 86-113% for water samples and 85-92% for blue-green algae samples. Selectivity of the IAC clean-up was proven by comparison with non-specific solid phase extraction using octadecylsilica (ODS) sorbent. Results obtained using LC/UV after IAC clean-up agreed well with results obtained using liquid chromatography and mass spectrometry detection (LC/MS and LC/MS/MS) after SPE-C18 clean-up, allowing therefore to validate the resulting technique.  相似文献   

14.
In our project, ghrelin analogs possessing enhanced stability and potential to significantly increase food intake were used. Three newly synthesized ghrelin analogs with fatty acid residues consisting of 8, 10, and 14 carbon atoms were studied. The main goal of this work was to develop a suitable analytical method for the determination of the stability of the novel ghrelin analogs in plasma. An appropriate liquid chromatography‐mass spectrometry method was developed and optimized. The results obtained were compared with the data measured by using a commercial enzyme‐linked immunosorbent assay kit, and a good correlation was found. A preparation strategy for plasma samples was optimized and consisted of simple dilution of the plasma samples followed by direct injection onto a very short monolithic column in combination with mass spectrometric detection. The developed analytical method was utilized for the determination of the stability of the prepared lipopeptides in plasma and for the quantification of the lipopeptides in a preliminary pharmacokinetic study. The feasibility of the developed separation method was clearly demonstrated. Accuracy and precision were within 80–120% and ±20% limits, respectively. Calibration curves were constructed in the range of 1–250 μg/mL.  相似文献   

15.
The paper describes the characterisation and application of sol-gel columns prepared by entrapping anti-chloramphenicol (CAP) antibodies. Retention of CAP in the column was caused by specific interactions with the anti-CAP antibodies and not by non-specific adsorption to the sol-gel glass. After optimising important operation conditions, e.g. feeding medium, feeding flow-rate, elution medium, elution flow-rate and elution volume, the sol-gel columns were included in a clean-up procedure developed to determine CAP in shrimp. The selectivity of the columns was high enough to efficiently remove interfering matrix compounds. Due to the chromatographic conditions applied retention of cross-reacting substances in the immunoaffinity column did not pose a problem. CAP recovery of the analytical method was 68% with a relative standard deviation of 4% (n=4). In spite of applying highly complex shrimp extracts the columns could be used for clean-up of at least 12 samples. However, when detection of CAP is carried out with an UV detector the analytical method has a relatively poor sensitivity (LOD=1.8 ng/g, S/N=3). The most obvious way is to replace the UV detector by a detector based on an inherently more sensitive and selective detection principle, like a mass spectrometer.  相似文献   

16.
Tetrabromobisphenol A is the most widely used brominated flame retardant. A sensitive and selective enzyme-linked immunosorbent assay (ELISA) for the detection of tetrabromobisphenol A was developed. The limit of detection and the inhibition half-maximum concentration of tetrabromobisphenol A in phosphate buffered saline with 10% methanol were 0.05 and 0.87 ng mL−1, respectively. Cross-reactivity values of the ELISA with a set of important brominated flame retardants including tetrabromobisphenol A-bis(2,3-dibromopropylether), 2,2′,6,6′-tetrabromobisphenol A diallyl ether, hexabromocyclododecane, 1,2-bis(pentabromodiphenyl) ethane, 1,2-bis(2,4,6 tribromophenoxy) ethane, bis(2-ethylhexyl)-3,4,5,6-tetrabromophthalate, 2-ethylhexyl-2,3,4,5-tetrabromobenzoate, and polybrominated diphenyl ethers were <0.05%. Concentrations of tetrabromobisphenol A determined by ELISA in the soils from farmlands, the soils from an e-waste recycling site, and the sediments of a canal were in the range of non-detectable–5.6 ng g−1, 26–104 ng g−1 and 0.3–22 ng g−1 dw, respectively, indicating the ubiquitous pollution of tetrabromobisphenol A. The results of this assay for 16 real world samples agreed well with those of the liquid chromatography–tandem mass spectrometry method, indicating this ELISA is suitable for screening of tetrabromobisphenol A in environmental matrices.  相似文献   

17.
Vardenafil is a phosphodiesterase-5 (PDE-5) inhibitor for the treatment of erectile dysfunction (ED). Undeclared vardenafil and related analogues adulterated in herbal products are a threat to public health. To screen vardenafil and its analogues in herbal matrix rapidly, an immunoassay based on a group specific monoclonal antibody (McAb) was developed.Glutaraldehyde was used to link vardenafil to immunogen and coating-antigen, respectively. Through the assessment of the structural specificity of eight anti-vardenafil McAbs, the McAb of 4B9 was characterized as being specific to the common structure of vardenafil and its analogues. An indirect competitive enzyme-linked immunosorbent assay (ic-ELISA) was established based on this McAb, the limit of detection of vardenafil was 5.0 ng mL−1, the calibration curve was linear from 5.0 to 40 ng mL−1 (R2 = 0.952) with an IC50 value of 18.2 ng mL−1. In the extracts of 20 Chinese traditional drugs, the detection capability (CCβ) of vardenafil was 0.08 mg g−1, the recoveries were 76-116% and the coefficients of variation (CV%) were 9.7%-16.2%. The ic-ELISA was in good agreement with LC-UV when detected herbal products containing vardenafil and its analogue.The method is a suitable tool for screening vardenafil and its analogues as illegal additives in herbal products.  相似文献   

18.
采用活性酯法将半抗原玉米赤霉醇-16-羧丙基醚与辣根过氧化物酶连接,制备了三种结合比的酶标抗原。通过紫外吸收法和直接非竞争ELISA法对酶标抗原的偶联结果和抗原性进行鉴定。最终选择结合比为1.3∶1的酶标抗原建立直接竞争ELISA检测方法。并对建立的直接竞争ELISA(DC-ELISA)与间接竞争ELISA(IC-ELISA)方法在检出限、检测线性范围、检测时间和二抗的使用方面进行了比较。  相似文献   

19.
An immunoaffinity column for the selective extraction and concentration of the herbicide triclopyr from water samples and quantification on line by HPLC has been developed. The immunoaffinity device was prepared by immobilising triclopyr antibodies to hydrazide derivatized azlactona beds. Efficient desorption of bound triclopyr was achieved with 70% ethanol/water solution. The column was evaluated regarding selectivity, recovery, capacity, saturation volume and reusability. Obtained results show that immunoaffinity chromatography (IAC) can be used for quantitative extraction, concentration and determination of triclopyr from water samples.  相似文献   

20.
Antibody-based therapeutic agents and other biopharmaceuticals are now used in the treatment of many diseases. However, when these biopharmaceuticals are administrated to patients, an immune reaction may occur that can reduce the drug's efficacy and lead to adverse side-effects. The immunogenicity of biopharmaceuticals can be evaluated by detecting and measuring antibodies that have been produced against these drugs, or antidrug antibodies. Methods for antidrug antibody detection and analysis can be important during the selection of a therapeutic approach based on such drugs and is crucial when developing and testing new biopharmaceuticals. This review examines approaches that have been used for antidrug antibody detection, measurement, and characterization. Many of these approaches are based on immunoassays and antigen binding tests, including homogeneous mobility shift assays. Other techniques that have been used for the analysis of antidrug antibodies are capillary electrophoresis, reporter gene assays, surface plasmon resonance spectroscopy, and liquid chromatography-mass spectrometry. The general principles of each approach will be discussed, along with their recent applications with regards to antidrug antibody analysis.  相似文献   

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