金黄色葡萄球菌肠毒素P双抗夹心酶联免疫检测方法的建立

本研究目的是建立一种快速检测金黄色葡萄球菌新型肠毒素SEP的双抗夹心酶联免疫方法。通过对单克隆抗体和抗血清质量浓度、辣根过氧化物酶标记的羊抗兔Ig G(Ig G/HRP)最佳稀释度、不同种类包被缓冲液、封闭时间、抗原包被时间、Ig G/HRP作用时间以及四甲基联苯胺(TMB)显色时间等条件进行优化;并采用灵敏度、批内和批间变异和加标回收率等对方法进行评价。结果表明:该方法中抗SEP单克隆抗体的最佳稀释质量浓度为3.28μg/m L,抗SEI兔血清的质量浓度为3.14μg/m L,酶标二抗稀释度1:3000,1×磷酸缓冲盐溶液(pH 7.4)为最佳包被缓冲液,封闭时间为1 h,抗原孵育时间为90 min,酶标二抗反应时间为30 min,TMB显色时间15 min。该方法回归方程为y=0.0313x+0.0262,R2=0.9946。灵敏度为1.80μg/m L,精密度批内变异低于6%,批间变异低于15%,对LB肉汤、牛肉糜和熟米饭回收率达90%以上。     

金黄色葡萄球菌肠毒素P双抗夹心酶联免疫检测方法研究

本研究目的是建立一种快速检测金黄色葡萄球菌新型肠毒素 SEP 的双抗夹心酶联免疫方法。通过对单克隆抗体和抗血清质量浓度、辣根过氧化物酶标记的羊抗兔 Ig G（Ig G/HRP）最佳稀释度、不同种类包被缓冲液、封闭时间、抗原包被时间、Ig G/HRP作用时间以及四甲基联苯胺（TMB）显色时间等条件进行优化;并采用灵敏度、批内和批间变异和加标回收率等对方法进行评价。结果表明：该方法中抗 SEP 单克隆抗体的最佳稀释质量浓度为 3.28 μg/m L,抗 SEI 兔血清的质量浓度为 3.14 μg/m L,酶标二抗稀释度 1:3000,1×磷酸缓冲盐溶液（p H 7.4）为最佳包被缓冲液,封闭时间为 1 h,抗原孵育时间为 90 min,酶标二抗反应时间为 30 min,TMB 显色时间 15 min。该方法回归方程为 y=0.0313x+0.0262,R2=0.9946。灵敏度为 1.80 μg/m L,精密度批内变异低于 6%,批间变异低于 15%,对 LB 肉汤、牛肉糜和熟米饭回收率达 90%以上。     

间接竞争ELISA法检测坚果类过敏原特异性研究

以腰果蛋白为过敏抗原,腰果蛋白致敏的阳性小鼠血清作为一抗,羊抗鼠Ig E-HRP为二抗建立双抗体间接酶联免疫吸附实验(ELISA)体系,通过棋盘法确定腰果蛋白最佳反应条件工作浓度为15.92μg/m L,最佳一抗稀释度均为1∶400,最佳酶标二抗的稀释度为1∶1000,腰果蛋白浓度为1.99μg/m L。并用该方法分别对腰果、核桃、榛子、开心果、板栗、杏仁等六种坚果进行检测分析,未发现有交叉反应,本实验建立的间接竞争性ELISA诊断方法具有良好的敏感性和特异性,为坚果过敏性食品的监测及时而准确的诊断奠定了基础。     

检测阪崎肠杆菌间接ELISA方法的建立

建立阪崎肠杆菌(Enterobacter Sakazakii,ES)特异性抗体间接ELISA检测方法,以期作为融合后杂交瘤细胞株的筛选体系。应用灭活的阪崎肠杆菌菌体为抗原,筛选最佳反应条件,建立检测该病原菌的酶联免疫吸附检测方法。通过对ELISA反应条件优化,确定菌体抗原包被的最适工作浓度为2×105mL-1,4℃包被过夜;5%脱脂奶粉进行封闭;血清最佳稀释比为1∶2 000;酶标抗体最适稀释度为1∶1 000倍;最后确定37℃显色10 min,检测灵敏度达到103mL-1。该方法的建立为阪崎肠杆菌单克隆抗体制备过程中阳性杂交瘤细胞株的筛选提供有效手段和奠定实验基础。     

金黄色葡萄球菌新型肠毒素I双抗夹心-酶联免疫检测方法的建立

目的：建立简便、灵敏检测金黄色葡萄球菌肠毒素I（staphylococcal enterotoxin I,SEI）的双抗夹心酶联免疫吸附方法（double-antibody sandwich-enzyme linked immunosorbent assay,DAS-ELISA）。方法：利用DAS-ELISA检测程序确定单克隆抗体、抗血清、辣根过氧化物酶（horseradish peroxidase,HRP）标记的羊抗兔IgG（IgG/HRP）的最佳稀释度,再通过检测不同包被缓冲液、封闭时间、抗原包被时间、IgG/HRP作用时间以及四甲基联苯胺（3,3’,5,5’-tetramethylbenzidine,TMB）显色时间条件下的OD450 nm值对实验条件进行优化,最后用灵敏度、批内变异、批间变异和加标回收率指标对方法进行评价。结果：抗SEI单克隆抗体的最佳稀释质量浓度为2.89 mg/L,抗SEI兔血清稀释度1∶2 000,酶标二抗稀释度1∶6 000;1×磷酸缓冲盐溶液（pH 7.4）为最佳包被缓冲液;最佳封闭时间、抗原孵育时间、酶标二抗孵育时间和TMB显色时间分别为60、90、30 min和15 min。该方法的回归方程为y=0.040 9x＋0.042 9,R2=0.993 3;灵敏度为0.5 μg/L,精密度批内变异低于10%,批间变异低于15%,除巴氏杀菌牛乳外,对生理盐水、熟牦牛肉糜、大米饭和超高温瞬时灭菌牛乳回收率达90%以上。结论：本研究建立了一种快速检测SEI的双抗夹心方法。     

直接竞争化学发光酶免疫法检测呋喃妥因代谢物

建立检测动物组织中呋喃妥因代谢物的直接竞争化学发光酶免疫法。采用棋盘法确定抗体和酶标抗原的最佳稀释度,通过单因素试验优化包被条件、封闭液种类和竞争反应时间,建立直接竞争抑制曲线,并对方法的灵敏度、特异性、准确度和精密度进行方法学评价。结果表明,经优化,最佳反应条件为抗体稀释度1∶4 000,酶标抗原稀释度1∶80,包被条件为37 ℃ 2 h后4 ℃过夜,封闭液为1%牛血清白蛋白,竞争反应1 h。该方法的线性检测范围为0.030～10.595 ng/mL,IC50为0.559 ng/mL;加标回收率为84.9%～103.4%,批内变异系数为3.4%～7.8%,批间变异系数为4.7%～11.8%;除与呋喃妥因原药交叉反应率为36.2%,与其他结构类似物及衍生化试剂交叉反应率均小于0.1%。该方法灵敏、准确,可用于动物组织中呋喃妥因代谢物的快速筛查。     

白酒中邻苯二甲酸二乙酯的化学发光酶联免疫分析方法

以邻苯二甲酸二乙酯(diethyl phthalate,DEP)为研究目标,以4-氨基邻苯二甲酸二乙酯为半抗原,通过重氮法偶联载体蛋白并免疫动物,制备针对DEP的特异性兔多克隆抗体。通过棋盘滴定法和单因素实验确定最佳的实验参数,即包被抗原浓度为50 ng/m L,4℃环境下包被12 h;抗体用T液稀释;药物缓冲液选用p H 5.4、0.005 mol/L的PBS缓冲液;酶标二抗用P液稀释,稀释度为1/3000;反应时间是:一抗∶二抗=30 min:40 min。基于此建立了间接竞争化学发光酶联免疫法检测DEP。该方法对DEP的最低检测限(LOD)为3.09 ng/m L,检测范围(IC20~IC80)为5.93~42.03 ng/m L,半抑制浓度(IC50)值为16.57 ng/m L,与14种结构类似物及功能类似物交叉反应均远低于0.5%,通过对白酒样品添加回收率的测定,证明了该方法的准确性,适用于白酒中DEP的快速检测。     

ELISA法快速检测水产品中副溶血性弧菌

以副熔血性弧菌抗原免疫新西兰大白兔获得特异性抗体,利用此抗体,进行间接竞争ELISA法实验,确定了抗原抗体最佳反应浓度和一抗稀释度分别为107cfu/mL和1:4000,酶标二抗IgG-HRP最佳工作稀释度为1:1000.以此方法分别对人工染菌水产品及实际水产品进行检测,检测下限为104cfu/mL,检测时间为8h;而经8h增菌后,其检测下限为103cfu/mL.此法与常规方法检测结果完全一致,具有很高的实际应用价值.     

草甘膦单克隆抗体的制备及酶联免疫分析方法的建立

目的 制备出草甘膦(glyphosate,GLY)单克隆抗体,建立间接竞争酶联免疫吸附法(enzyme linked immunosorbent assay, ELISA)快速检测茶叶中GLY的方法。方法 首先合成GLY完全抗原(包被原和免疫原),通过免疫小鼠成功制备出GLY单克隆抗体。根据ELISA的检测流程,采用棋盘法确定最佳包被抗原和抗体的稀释倍数,确定最佳包被的温度和时间,并确定最佳加入一抗、二抗后反应时间,建立检测方法并对其性能进行评价。结果 GLY包被抗原和抗体的稀释倍数为1:2000,包被温度为37℃、包被时间为90 min,加入一抗、二抗后反应时间为60min。该方法的线性方程为Y=-0.2353X+0.6539(r²=0.9871),半抑制浓度(50%inhibiting concentration, IC₅₀)为4.508 ng/mL,检出限为1.18 ng/mL。变异系数均在10%以下,与异菌脲、多菌灵、三唑磷、甲基对硫磷、噻菌灵这5种标准品的交叉反应率均低于0.03%,在茶叶中加标回收率为90.86%～110.35%,...     

呋喃唑酮代谢物间接竞争化学发光酶免疫法的建立

建立快速检测动物源性食品中呋喃唑酮代谢物AOZ的间接竞争化学发光酶免疫法。利用对醛基苯甲酸(4-CBA)将AOZ衍生化为CPAOZ,利用活化酯法将CPAOZ与卵清蛋白(OVA)偶联,生成完全抗原CPAOZ-OVA。对包被原与抗体的最佳稀释倍数、封闭液浓度、竞争时间、酶标二抗稀释倍数进行优化,建立标准曲线,同时对方法的特异性进行评价。结果表明:包被抗原最佳稀释倍数为2000倍,抗体的最佳稀释倍数为20000倍、封闭液为2%脱脂乳粉、竞争时间为2 h、二抗最佳稀释倍数为4000倍;线性范围是0.075~7.396 ng/m L,半抑制浓度IC_(50)为0.74 ng/m L,对呋喃唑酮原药的交叉反应率为23.4%,与其他结构类似物及衍生化试剂的交叉反应率均小于0.1%。该方法灵敏度高、特异性好,可为监管部门对于快速检测动物源性食品中AOZ提供依据。     

Reliable identification of grapevine rootstock varieties using RAPD PCR on woody samples

Since grapevine ( Vitis spp .) rootstock material is being traded increasingly as disbudded woody material a lack of distinctive morphological features on such material necessitates an alternative and reliable means of identification. Methods described here were developed for rapid and efficient extraction of DNA from woody samples rich in phenolic compounds and polysaccharides, and for subsequent identification of varieties by RAPD PCR. Using these methods, and with the application of only one selected RAPD primer, we were able to differentiate sixteen rootstock varieties, including the seven varieties most commonly used in Germany. Problems commonly encountered with reproducibility of RAPD patterns were avoided by choosing primers with a dinucleotide sequence and a high G/C content that allowed a rather high annealing temperature of 45°C. Methods described here should also be useful for other horticultural crops, especially those with woody tissues rich in phenolic compounds and polysaccharides.     

An internet compendium of analytical methods and spectroscopic information for monomers and additives used in food packaging plastics

An internet website (http://cpf.jrc.it/smt/) has been produced as a means of dissemination of methods of analysis and supporting spectroscopic information on monomers and additives used for food contact materials (principally packaging). The site which is aimed primarily at assisting food control laboratories in the European Union contains analytical information on monomers, starting substances and additives used in the manufacture of plastics materials. A searchable index is provided giving PM and CAS numbers for each of 255 substances. For each substance a data sheet gives regulatory information, chemical structures, physico-chemical information and background information on the use of the substance in particular plastics, and the food packaging applications. For monomers and starting substances (155 compounds) the infra-red and mass spectra are provided, and for additives (100 compounds); additionally proton NMR are available for about 50% of the entries. Where analytical methods have been developed for determining these substances as residual amounts in plastics or as trace amounts in food simulants these methods are also on the website. All information is provided in portable document file (PDF) format which means that high quality copies can be readily printed, using freely available Adobe Acrobat Reader software. The website will in future be maintained and up-dated by the European Commission's Joint Research Centre (JRC) as new substances are authorized for use by the European Commission (DG-ENTR formerly DGIII). Where analytical laboratories (food control or other) require reference substances these can be obtained free-ofcharge from a reference collection housed at the JRC and maintained in conjunction with this website compendium.     

Aroma characterization of various apricot varieties using headspace–solid phase microextraction combined with gas chromatography–mass spectrometry and gas chromatography–olfactometry

The characterization of the aromatic profile of several apricot cultivars with molecular tracers in order to obtain objective data concerning the aromatic quality of this fruit was undertaken using headspace–solid phase microextraction (HS–SPME). Six apricot cultivars were selected according to their organoleptic characteristics: Iranien, Orangered, Goldrich, Hargrand, Rouge du Roussillon and A4025. The aromatic intensity of these varieties measured by HS–SPME–Olfactometry were defined and classified according to the presence and the intensity of grassy, fruity and apricot like notes. In the six varieties, 23 common volatile compounds were identified by HS–SPME–GC–MS. Finally, 10 compounds, ethyl acetate, hexyl acetate, limonene, β-cyclocitral, γ-decalactone, 6-methyl-5-hepten-2-one, linalool, β-ionone, menthone and (E)-hexen-2-al were recognized by HS–SPME–GC–O as responsible of the aromatic notes involved in apricot aroma and considered as molecular tracers of apricot aromatic quality which could be utilized to discriminate apricot varieties.     

Tests of potential functional barriers for laminated multilayer food packages. Part I: Low molecular weight permeants

The advent of the functional barrier concept in food packaging has brought with it a requirement for fast tests of permeation through potential barrier materials. In such tests it would be convenient for both foodstuffs and materials below the functional barrier (sub-barrier materials) to be represented by standard simulants. By means of inverse gas chromatography, liquid paraffin spiked with appropriate permeants was considered as a potential simulant of sub-barrier materials based on polypropylene (PP) or similar polyolefins. Experiments were performed to characterize the kinetics of the permeation of low molecular weight model permeants (octene, toluene and isopropanol) from liquid paraffin, through a surrogate potential functional barrier (25 μm-thick oriented PP) into the food simulants olive oil and 3% (w/v) acetic acid. These permeation results were interpreted in terms of three permeation kinetic models regarding the solubility of a particular model permeant in the post-barrier medium (i.e. the food simulant). The results obtained justify the development and evaluation of liquid sub-barrier simulants that would allow flexible yet rigorous testing of new laminated multilayer packaging materials.     

Analysis of benzo[a]pyrene in spiked fatty foods by second derivative synchronous spectrofluorimetry after microwave-assisted treatment of samples

A simple, rapid and inexpensive method has been developed for the determination of benzo[a     

The development of reference materials for paralytic shellfish poisoning toxins in lyophilized mussel. II: Certification study

This paper describes the second part of a project undertaken to develop certified mussel reference materials for paralytic shellfish poisoning toxins. In the first part two interlaboratory studies were undertaken to investigate the performance of the analytical methodology for several PSP toxins, in particular saxitoxin and decarbamoyl-saxitoxin in lyophilized mussels, and to set criteria for the acceptance of results to be applied during the certification exercise. Fifteen laboratories participated in this certification study and were asked to measure saxitoxin and decarbamoyl-saxitoxin in rehydrated lyophilized mussel material and in a saxitoxin-enriched mussel material. The participants were allowed to use a method of their choice but with an extraction procedure to be strictly followed. The study included extra experiments to verify the detection limits for both saxitoxin and decarbamoyl-saxitoxin. Most participants (13 of 15) were able to meet all the criteria set for the certification study. Results for saxitoxin.2HCl yielded a certified mass fraction of <0.07 mg/kg in the rehydrated lyophilized mussels. Results obtained for decarbamoyl-saxitoxin.2HCl yielded a certified mass fraction of 1.59+/-0.20 mg/kg. The results for saxitoxin.2HCl in enriched blank mussel yielded a certified mass fraction of 0.48 +/- 0.06 mg/kg. These certified reference materials for paralytic shellfish poisoning toxins in lyophilized mussel material are the first available for laboratories to test their method for accuracy and performance.     

Announcing a new international peer-reviewed journal:Food Science and Human Wellness now accepting manuscript submission in English

<正>We are pleased to announce the launch of a new international peer-reviewed journal-Food Science and Human Wellness,ISSN 2213-4530,which is an open access journal,produced and hosted by Elsevier B.V.on behalf of Beijing Academy of Food Sciences.Food Science and Human Wellness is an international peer-reviewed English journal that provides a forum for the dissemination of the     

Chinese CTP Market

According to Printing and Printing Equipment Industries Association of China（PEIAC）＇s statistics to the plate manufucturer in China, in 2013, the actual offset plate production has reached 346 million square meters in China. Among them, the CTP production volume was 245 million square meters, up by 11% than that of last year; the total sales of the CTP plate was 239 million square meters, up by 13%.     

Preparatory Work of Print China 2015 is Going Smoothly

正Held at Guangdong Modern International Exhibition Center,Print China 2015 will cover 7exhibition halls,besides the original Hall No.3,4,5,6,7,the newly built F zone of Hall 3 will be used too.The total area will be140,000 square meters.Hall 3:Offset and large printing equipment,package printing equipment,post press