基于pH敏感相分离技术的新型荧光免疫测定体系

In this paper, it was discovered that a novel pH-sensitive copolymer of N-isopropylacrylamide (NIP) and N-(3-dimethylaminopropyl)methacrylamide (DMAPM) could be gotten by polymerization. The phase transition pH (pHtr) of P(NIP-DMAPM) polymer was found to be 7.4 at 37℃. The polymer was precipitated out of water above a critical pH=7.4 and re-dissolved below pH----7.4. The characteristic of this polymer made it possible to carry out the immunochemical steps of an immunoassay in a true solution and then to quickly separate the resulting product from the reaction mixture. In a competitive fluorescence immunoassay, the standard rabbit IgG and rabbit IgG immobilized on P(NIP-DMAPM) first competitively reacted with the fluorescein isothiocyanate (FITC) labeled antibody, then the pH of solution was adjusted above the pHtr of polymer to precipitate the polymer-immune complex,and the polymer-immune complex precipitate was separated and re-dissolved by the adjustment of pH, finally the FITC-labeled antibody in the immune complex was quantified by fluorescence measurement. The calibration graph for rabbit IgG was linear over the range of 100-1000 ng/mL with a detection limit of 11 ng/mL. The method is rapid, sensitive and simple. Owing to neutral pHtr of P(NIP-DMAPM), the damage to antigen-antibody immune complex was greatly decreased in the course of separation. In addition, a sandwich enzyme-linked fluorescence immunoassay method for the determination of human IgG was also developed, showing that the pH-sensitive phase separating immunoassay could be performed in the competitive method as well as the sandwich method.     

以pH敏感相分离高分子为载体的酶联荧光免疫分析法测定人IgG

p H敏感高分子因其独特的 p H敏感性质而在药物的控制释放 [1,2 ] 、分子分离 [3 ] 以及生物传感器 [4 ]等方面得到应用 .应用于免疫分析时 ,要求 p H敏感高分子在溶液 p H 7.4左右波动时做出响应 ,过多偏离生理 p H会对免疫反应生成的抗原 -抗体复合物造成不同程度的破坏 .目前 ,p H敏感高分子并未在免疫分析中广泛应用 ,这主要是由于高分子的相转变 p H大多在 4或 1 0左右[5,6] .我们 [7] 曾合成了3 7℃下相转变 p H在 5 .6左右的 p H敏感高分子 ,并将其作为免疫反应载体 ,建立了乙肝表面抗原的分析系统 ,虽然其相转变 p H比以往的高…     

双嘧达莫对胰腺癌细胞内抗肿瘤药物6-巯基嘌呤浓度的影响及6-巯基嘌呤的荧光分光光度法测定

建立了细胞内抗肿瘤药物6 巯基嘌呤的荧光光度分析新方法,系统地研究了在KMnO4氧化条件下酸度、温度、时间等因素对6 巯基嘌呤相对荧光强度的影响。在荧光激发波长310nm和发射波长413nm下,溶液中6 巯基嘌呤的荧光强度与其浓度在4.0×10-11～4.0×10-6mol L范围内呈良好的线性关系,方法的检出限为8.2×10-12mol L。用建立的方法研究了不同浓度核苷载体阻断剂(双嘧达莫)对胰腺癌细胞内6 巯基嘌呤浓度的影响情况。统计学检验结果表明,细胞膜上核苷载体的阻断能提高细胞内抗肿瘤药物的浓度。     

四氨基铝酞菁作为过氧化物酶模拟酶新型红区荧光底物的研究

本文按照文献[1]合成了一种优良的红区荧光探针－四氨基铝酞菁（TAAIPc,在强酸性介质中,它的最大激发与最大发射波长分别在610nm和678nm处）,并将它作为过氧化物酶模拟酶的红区荧光底物用于痕量过氧化氢的测定。由于在长波区具有荧光的天然物质很少,且溶液体系的散射光强度与1／λ^4成正比,因而在长波处进行样品测定时可以很好地避开背景荧光和散射光的干扰,检测限可得到较大的改善。     

用四磺基铝酞菁直接测定血清中白蛋白

以红区荧光染料四磺基铝酞菁（ＡｌＳ４Ｐｃ）为探针建立了荧光猝灭法测定白蛋白的新方法。考察了各种影响因素。厚佳实验条件下,该方法的线性区间０．１０－４．５ｍｇ／Ｌ,检测限为４０μｇ／Ｌ。将该方法用于人血清样品中白蛋白的直接测定并与临床方法（溴甲酚绿法）比较,二者符合良好。     

新型近红外试剂的合成及其现场二聚体与DNA作用的研究

合成了一种新型近红外阴离子染料,并对其水溶液及阳离子表面活性剂ＣＴＡＢ存在下的吸收荧光光谱进行了研究。结果表明,低浓度的ＣＴＡＢ与该近红外阴离子染料形成离子缔合物而使阴离子染料的荧光强度降低,当ＣＴＡＢ的浓度进一步加大时,其胶束前预聚集促使该染料形成非荧光二聚体,导致荧光急剧猝灭。     

Ultrastructures in the Spirotheca of Fusulinella (Fusulinid foraminifer)

An SEM study has been conducted to examine the ultrastructures in the spirotheca of Fusulinella and to reveal the ultra-features of the basic layers consisting of the spirotheca of Fusulinella. The study has demonstrated that the diaphanotheca in the spirotheca of Fusulinella could be considered as a secondary structure.     

Near-Infrared Hydrophobic Probes as Molecular Light Switch for CMC Determination of Triton X-100 Solution

The fluorescence behavior of two near-infrared (NIR) chromophores with linear alkyl chains of different lengths, 2-[4′chloro-7′(3″ethyl-2″benzothiaolinylidene)-3′,5′-(1″′3′″-propanediyl)-1′3′,5′-heptantriene-1′-yL]-3-ethylbenzothiazolium iodide (Probe Ⅰ) and 2-[4′chloro-7′(3″hexadecyl-2″benzothiazolinylidene)-3′,5′-(1′″,3′″-propanediyl)-1′,3′,5′-heptantriene-1′-yl]-3-ethylbenzothiazolium iodide (Probe Ⅱ), in aqueous solution containing different concentrations of surfactants was studied. The fluorescence of the probe with a short chain (probe Ⅰ) was completely quenched in water and aqueous solution containing a low concentration (below the critical micelle concentration,CMC) of surfactant Triton X-100. However, the fluorescence reappeared and reached maximum rapidly once the concentration of the surfactant approached the CMC. The probe with a long chain (probe II) displayed a similar fluorescence behavior but more dramatically fluorescent recovery in Triton X-100 system, which gave a direct in- dication for the micelle forming process and provided a simple method for the determination of the critical micelle concentration of the surfactant. The CMC values determined by this method were in good agreement with those obtained by other techniques. The fluorescence behavior of the two probes in other surfactant systems was also investigated.     

L-组氨酸分光光度法测定消毒剂中的邻苯二甲醛

邻苯二甲醛与L-组氨酸在pH8.0介质中可形成在376mm处有最大吸收的复合物。以水为空白,邻苯二甲醛的浓度与其复合物的吸光度在1.3×10 6～2.6×10 5mol/L范围呈良好的线性关系,方法的检出限为5.54×10 6mol/L,表现摩尔吸光系数为4.94×103L·mol 1·CM 1。本法操作简单、灵敏度高,可方便地用于消毒剂中邻苯二甲醛的快速测定。