多重PCR-液相芯片技术检测13个品系转基因玉米

为建立多重PCR-液相芯片检测13个品系的转基因玉米的方法,针对BT11,BT176,Mon810,Mon863,T25,GA21,NK603,TC1507,Mon89034,Mir162,Mon88017,MIR604和BVLA430101这13种玉米品系的侧翼序列,设计合成了品系特异性引物/探针。在生物素标记的PCR扩增产物与固定在荧光编码微球上的品系特异探针杂交后,对微球进行流式检测。试验结果显示,13种转基因玉米的引物和探针具有较高的特异性,引物/探针相互之间无交叉扩增和非特异杂交,大部分转基因玉米品系的检测灵敏度达到0.1%水平,符合欧盟和其他国家有关转基因产品标识的要求。本方法的检测效率和准确性均高于传统方法,可作为进出口转基因产品和国内转基因检测的有效方法。     

Determination of porcine gelatin in edible bird's nest by competitive indirect ELISA based on anti-peptide polyclonal antibody

Competitive indirect enzyme-linked immunosorbent assay (ELISA) was developed for rapid detection of porcine gelatin in edible bird's nest (EBN). Three ELISAs were developed by using polyclonal rabbit antibodies against porcine species-specific amino acid sequences of collagen α2 (I) chain (pAb1 and pAb2) and α1 (I) chain (pAb3). The limit of detection (IC₁₅) of the three ELISAs was 0.033, 0.082 and 0.052 μg/mL respectively. The median inhibitory concentration (IC₅₀) of pAb1, pAb2 and pAb3 was 0.265, 0.394 and 0.228 μg/mL respectively, as well as able to recognise porcine and bovine gelatins. pAb1 showed slight cross-reactivity with cave nest and egg white, while pAb2 exhibited slight cross-reactivity with blood cave nest and egg white. No cross-reactivity was observed with EBNs and egg white for pAb3. The recoveries of porcine gelatin spiked EBNs were in the range of 62.8–125.4% with intra- and inter-day coefficient of variants (CVs) of 2.9–5.4% and 4.7–9.6% respectively when using pAb3. Taking into account all abovementioned factors, pAb3 appeared sufficient for EBN authentication.     

食品中马源性成分的实时荧光PCR检测

针对马线粒体DNA细胞色素b基因设计特异性引物和探针,建立食品中马源性成分实时荧光PCR检测方法,并经特异性和灵敏度试验验证其可行性。结果表明:该体系可扩增马DNA片段,长度为127 bp,其他常见畜、禽肉成分均无法正常扩增。该体系的检测灵敏度为1.25 pg马DNA和质量分数0.001%马肉粉。经市售食品的检测验证,表明所建立的马引物探针体系具有特异性好、灵敏度高、快速、高效等优点,可用于对食品中马源性成分的掺假鉴别检测。     

食源性病原菌分型方法研究进展

目前食源性病原菌常用的分型方法主要包括血清学分型、脉冲场凝胶电泳分型、多位点序列分型、多位点可变数目串联重复序列分型等, 在食源性病原菌的监测、传染源的追踪、流行病监测等方面具有重要意义。本文就食源性病原菌常用的分型方法及其应用情况进行综述。     

Authentication of Edible Bird's nests by TaqMan-based real-time PCR

Edible Bird's nests (EBN) have been adulterated with less expensive materials, including white fungus, agar–agar, fried pigskin, egg white and red seaweed, for several years. To protect consumers and regulate the EBN market, it is necessary to establish a robust method for detecting these adulterants in EBN. Herein, we established a TaqMan-based real-time polymerase chain reaction (PCR) assay to specifically detect EBN component and four common adulterants: white fungus, agar, pigskin and egg white. Therefore, five sets of primers and probes were designed for these five components. The assays were specific and reproducible, and the relative detection limits were 0.5% EBN in white fungus, 0.001% white fungus in EBN, 0.5% agar in EBN, 0.001% fried pigskin in EBN and 1% egg white in EBN. These detection levels are capable of effectively detecting the adulterants in commercial samples.     

肉类调理食品中细菌多样性的分析

肉类调理食品方便快捷,营养美味,深受消费者青睐,但其丰富的营养物质容易造成微生物的滋生,影响食品品质和消费者健康。高通量测序技术可以全面、准确的研究肉类调理食品中微生物群落结构,为微生物防控和标准化生产提供理论基础。本文通过均质提取法对肉类调理食品中微生物基因组进行提取,并以16S rRNA可变区V3-V4作为测序片段,分析细菌多样性。实验表明,4种肉类调理食品细菌多样性均较高,菌群结构具有一定的相似性,炸鸡块、骨肉相连和冷冻牛排的优势菌群是Anderseniella属,而羊肉串优势菌群是不动杆菌属,此外肉类调理食品中还存在芽胞杆菌属、梭菌属、泛菌属、假单胞菌属、嗜冷杆菌属和乳球菌属等。本论文明确了使用均质提取法对肉类调理食品中微生物进行16S rRNA V3-V4区测序分析,为后续大规模菌群研究提供思路和方法。