Single cell degenerate oligonucleotide primer-PCR and comparative genomic hybridization with modified control reference

For investigating the possibility of applying degenerate oligonucleotide primer PCR (DOP-PCR) and comparative genomic hybridization (CGH) technique to analyses of genomic genetics in a single cell, the whole genomic DNA of a single cell with XX, XY, XO, XXY, +13 or +21 was amplified by DOP-PCR. Single cell DOP-PCR CGHs with conventional and modified control references, the genomic DNA and a single cell DOP-PCR product from normal male, were carried out respectively. The results showed that the average profile of the fluorescence intensity ratio in CGH with the genomic DNA as reference fluctuates much and that the standard deviation in about 30% haploid is beyond the normal limits. False positive hyper-representation was found to exist in X chromosome while trisomy 13 and 21 were not detected. However, the distributions of the mean and the standard deviation of the ratio in the CGH with DOP-PCR product as reference were quite acceptable. The copy number changes of chromosome X, Y, 13 and 21 were revealed. Those results suggested that there is unrandom unequal amplification in a single cell DOP-PCR. Using a single DOP-PCR product as reference can decrease its influence on CGH. Single cell DOP-PCR-CGH and its application in the genetic analyses of preimplantation embryo or fetal cell in maternal blood may be possible.     

Development of a species-specific PCR assay for authentication of Agkistrodon acutus based on mitochondrial cytochrome b gene

BackgroundAgkistrodon acutus, a traditional Chinese medicine, clinically used in the treatment of rheumatism, tumor, and cardiovascular and cerebrovascular diseases. Due to the unique medicinal value and the difficulty of artificial breeding of Agkistrodon acutus, the supply of Agkistrodon acutus on the market exceeds the demand, and a large number of its adulterants are found on the market. In this study, the cytb gene sequences of Agkistrodon acutus and 9 snakes were compared and analyzed, specific primers were designed, and specific PCR methods were established to detect Agkistrodon acutus medicinal samples on the market.ResultsThis method was successfully applied to distinguish the snake from other adulterated species, and tested 18 Agkistrodon acutus samples randomly purchased from six cities. Twelve samples were counterfeit and six were genuine. The standard reference material of Agkistrodon acutus was cloned by molecular cloning and sequencing, and the gene sequence difference with other species was significant. It shows that the region could be used as the fingerprint region of the target species.ConclusionsThe proposed method can be used as a species-specific marker and can be highly distinguished from other adulterated snake species, which is helpful to effectively avoid the problem of false sale of Agkistrodon acutus.How to cite: Yingnuo L, Yanshuang W, Mingcheng Li, et al. Development of a species-specific PCR assay for authentication of Agkistrodon acutus based on mitochondrial cytochrome b gene. Electron J Biotechnol 2021;49. https://doi.org/10.1016/j.ejbt.2020.07.005     

Detection of PCV2 DNA by SYBR Green I-based quantitative PCR

We developed an assay for the detection and quantitation of porcine circovirus type 2 (PCV2) with the SYBR Green I-based real-time PCR. The real-time PCR provides a broad dynamic range, detecting from 103 to 1011 copies of DNA per reaction. No cross-reactions were found in specimens containing PCV1. Because of the high sensitivity and specificity of the assay with a relatively rapid and simple procedure, real-time PCR can be used as a routine assay for the clinical diagnosis of PCV2 infection. In this study we applied real-time PCR assay to 80 clinical samples, collected from 40 pigs with postweaning multisystemic wasting syndrome (PMWS) and 40 healthy pigs in comparison with conventional PCR assay. In 56 of 80 samples, PCV2 DNA was de-tected by conventional PCR assay. All samples positive for PCV2 DNA in conventional PCR assay were also positive in real-time assay, and 12 of 24 samples that tested negative for PCV2 DNA in the conventional assay were tested positive in real-time PCR assay. Real-time PCR assay increased the number of samples in which PCV2 was detected by 15%. It is, therefore, considered to be a useful tool for the detection of PCV2.     

具有毒性质粒沙门菌荧光PCR快速检测试剂盒的研发

介绍了用于检测具有毒性质粒沙门菌的2种荧光PCR试剂盒（一种是荧光PCR染料法检测试剂盒,另一种是荧光PCR探针法检测试剂盒）的研制过程,2种试剂盒运用了自行设计的特异性引物和TaqMan探针,能同时特异性地从众多的沙门氏菌和非沙门氏菌中高效、快速、准确地检测出多种具有毒性质粒沙门氏菌,而对于不具有毒性质粒的沙门氏菌和非沙门氏菌均不能检出,可为食品检验和医疗诊断领域提供方便快捷检测具有毒素质粒沙门氏菌的荧光PCR试剂盒．     

通用型音频电压信号放大器的设计方法

提出音频电压放大器的设计原则,并通过实例介绍了整个放大器的设计步骤,为放大电路的设计提供一种新模式。     

含铬废水的测定与处理

研究了含铬废水的处理及微量铬的测定.用硫酸亚铁铵作还原剂将Cr(Ⅵ)还原为Cr(Ⅲ)，利用共陈淀原理，可以基本除去Cr(Ⅲ).此方法适用于含Cr(Ⅵ)废水的处理.体系中微量铬用增敏碘量法测定，增敏倍数是9.Cr(Ⅲ)的测定方法是用过量高碘酸盐氧化，钼酸盐掩蔽未反应的高碘酸盐，最后以碘量法滴定产生的碘酸盐.Cr(Ⅵ)在用饱和亚硫酸钠预先还原为Cr(Ⅲ)后，也可用该方法测定.当铬含量小于340μg时，其平均回收率是99.7％.     

PCR技术的应用及前景展望

综述现代生物技术PCR在分子生物学研究、医学、法学和生物化学等领域的多种应用,展望PCR技术广阔的发展前景     

集成运算放大器的误差分析

就集成运算放大器的一些主要参数为有限时所带来的误差进行了分析,并对不同参数的元件对结果的影响进行了讨论.     

一种稳健的基于主颜色的多目标跟踪算法

多目标跟踪是视频监控等领域的一项关键技术,该文提出一种基于主颜色的多目标跟踪算法,在算法中使用主颜色描述感兴趣目标,在卡尔曼滤波器预测的基础上利用基于主颜色的mean shift算法对各目标进行跟踪,接着利用目标跟踪位置与前景blob之间的关联矩阵来推理多目标跟踪问题中的各种情况,根据不同的情况对目标的位置、大小以及颜色信息做相应的更新。对大量图像序列的测试结果表明,该算法能够较好地处理遮挡,具有稳健的跟踪效果。     

MOLECULAR CLONING AND NUCLEOTIDES SEQUENCE ANALYSIS OF G_1 GENOME SEGMENT OF HANTAAN VIRUS Z_(10) STRAIN

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