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排序方式: 共有270条查询结果,搜索用时 15 毫秒
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2.
Gui Hong YAN Da XING* Shi Ci TAN Institute of Laser Life Science South China Normal University Guangzhou 《中国化学快报》2004,15(1):101-104
Electrochemiluminescence (ECL), like other chemiluminescence technique, offers high signal-to-noise ratio. Furthermore, it has the advantage over other chemiluminescence techniques of being initiated by a voltage potential. Thus, it provides a better-controlled luminescence. This technique has been used in measuring many kinds of organic and inorganic matters, and analyzing many kinds of antigen, antibody and hapten, such as carcinoembryonic antigen and alpha-fetoprotein, etc1-6. The ele… 相似文献
3.
Molecular mass distribution of sodium alginate by high-performance size-exclusion chromatography 总被引:8,自引:0,他引:8
Ci SX Huynh TH Louie LW Yang A Beals BJ Ron N Tsang WG Soon-Shiong P Desai NP 《Journal of chromatography. A》1999,864(2):199-210
A sensitive high-performance size-exclusion chromatography (HPSEC) method with simple UV detection was developed for the molecular mass analysis of sodium alginate. It was used to evaluate alginates of varying molecular mass and the results were compared with the viscosity measurements. This HPSEC method was sensitive to serve as the stability indicating method for alginate after storage under different conditions. The information of relative molecular mass distribution of alginate was provided with reference to pullulan molecular mass standards. The comparison of the HPSEC chromatograms of alginate, pullulan and dextran revealed the effect of chemical composition of a polysaccharide and its effect on apparent molecular mass distribution. 相似文献
4.
A procedure for the simultaneous time-resolved fluoroimmunoassay for phenobarbital and phenytoin, based on the use of europium- and samarium-labeled haptens, has been investigated. These lanthanide ions are bound to the haptens by means of the anhydride of diethylenetriaminepentaacetic acid. The antibody is immobilized onto immunoplate in which samples are assayed in competitive immunoassay. After the immunoreactions and dissociation with a fluorescence enhancement solution, the fluorescence intensity is measured. The detection limits of the assay are, respectively, 20 ng/ml for phenobarbital and 50 ng/ml for phenytoin. Results obtained with the proposed methods correlate well (CV <10%). The inter-reactions between phenobarbital, phenytoin, and their antibodies are studied. 相似文献
5.
In this paper, the voltammetric method was used for the first time to study the effect of Cisplatin-liposome on Hela cells. The results showed the voltammetric behavior of Hela cells was irreversible and the peak current had linear relationship with the cell number. With both Cisplatin-liposome concentration and treating time increasing, the peak current decreased. The peak current decreasing was in accordance with the nuclear damage and loss of mitochondrial membrane potential revealed by two-photon laser scanning microscopy and confocal laser scanning microscopy. This voltammetric method may provide a simple way to study the electron-transfer mechanism in drug-treating cells. 相似文献
6.
酶联免疫吸附法直接测定血清雌二醇 总被引:20,自引:0,他引:20
本合成了3种不同载体蛋白的雌二醇抗原,研究了载体蛋白免疫原性对雌二醇抗体产生的影响。应用酶联免疫吸附分析法测定了血清中雌二醇,浓度范围为5-160ng/ml(1.8×10^-^8-5.9×10^-^7mol/L).RSD%小于10.%,检测限为1.97ng/ml,相当于98.5pg/孔(按空白平均值的二倍标准偏差计算)。另外,本还建立了一种用考马斯亮蓝G-250测定半抗原与蛋白结合比的方法,提 相似文献
7.
Unlabeled fluoroimmunoassay with a europium chelate is described. The recommended method is simple because the complicated labeling process is omitted. The recovery of some samples ranges from 91 to 111%. The relative standard deviation of the method is less than 10%. The detection limit is about 10−10mol liter−1antigen. 相似文献
8.
The relative ability of peroxidase-like metallotetrakis(N-methylpyridiniumyl)porphyrins [Me-TMPyP, Me = Mn(III), Fe(III), Co(III), Ni(II), Cu(II), and Zn(II)] to catalyse the hydrogen peroxide oxidation of homovanillic acid to a fluorescent dimer has been studied. The complexes of Mn, Fe and Co are effective catalysts in the reaction, but the complexes of Ni, Cu and Zn are not. The catalytic behaviour of Mn-TMPyP, Fe-TMPyP and Co-TMPyP has been compared with that of HRP in both enzymatic and kinetic analysis. The sequence of peroxidase-like catalytic activity is Mn-TMPyP> Co-TMPyP> Fe-TMPyP. The catalytic activity of Mn-TMPyP is 84% of that of HRP. These Me-TMPyP (Me = Mn, Fe, and Co) compounds are good substitutes for HRP in enzymatic analysis. Traces of hydrogen peroxide and glucose can be determined with the Me-TMPyP systems. 相似文献
9.
Yuan-zong Li Hong-fei Liu Zhu-qing Dong Wen-bao Chang Yun-xiang Ci 《Microchemical Journal》1996,53(4):428-436
N,N′-Dicyanomethyl-o-phenylenediamine was synthesized with a 90% yield by a reaction ofo-phenylenediamine with chloroacetonitrile in triethylamine. Our experimental results showed that it was the effective fluorogenic substrate for horseradish peroxidase (HRP) and hemin. TheKmfor the HRP system was 48 μM,and that for hemin was 1.3 μM.Properties of the substrate were evaluated from the detection limits of enzymes and H2O2. The linear ranges for the determination of HRP and hemin were 21–150 pMand 2–20 nM,respectively. The linear range for the determination of H2O2using HRP or hemin was 18–140 and 60–1000 nM,respectively. The structural elucidation of the fluorescent product using NMR and mass spectral techniques was proposed to be 1,2-dihydro-2-imido-imidazo[1,2-a] quinoxaline. Based on the product structure and earlier reports, the possible reaction mechanism of HRP and the substrate was also proposed, i.e., two steps for ring closures, one step of isomerization, and a final step of oxidative dehydrogenation. 相似文献
10.