DNA的定量分析方法综述

核酸是重要的生命物质，它的定量分析是生命科学、临床检验及生化研究等领域的重要课题。本文首先总结了近年来脱氧核糖核酸DNA定量分析的新方法和新成果，然后从测定原理、特点及试剂等锌方面对各种新方法作了归纳及评述。     

DNA计算图的最小顶点覆盖问题

自1994年Adleman发表了第一篇关于DNA分子计算的文章以来,DNA计算迅速成为活跃的研究领域。利用DNA计算解决了图的最小顶点覆盖问题,在构造了合有6个顶点10条边的图的顶点集对应的数据池之后,进行了一系列的合成、杂交、清洗、变性等生物操作。得到所有覆盖对应的DNA序列,然后通过编址得到所要求的最小覆盖。     

Mass spectrometry-based protein-protein interaction techniques and their applications in studies of DNA damage repair

Proteins are major functional units that are tightly connected to form complex and dynamic networks.These networks enable cells and organisms to operate properly and respond efficiently to environmental cues.Over the past decades,many biochemical methods have been developed to search for protein-binding partners in order to understand how protein networks are constructed and connected.At the same time,rapid development in proteomics and mass spectrometry(MS)techniques makes it possible to identify interacting proteins and build comprehensive protein-protein interaction networks.The resulting interactomes and networks have proven informative in the investigation of biological functions,such as in the field of DNA damage repair.In recent years,a number of proteins involved in DNA damage response and DNA repair pathways have been uncovered with MS-based protein-protein interaction studies.As the technologies for enriching associated proteins and MS become more sophisticated,the studies of protein-protein interactions are entering a new era.In this review,we summarize the strategies and recent developments for exploring protein-protein interaction.In addition,we discuss the application of these tools in the investigation of protein-protein interaction networks involved in DNA damage response and DNA repair.     

Evaluation and application of an efficient plant DNA extraction protocol for laboratory and field testing

Nucleic acids in plant tissue lysates can be captured quickly by a cellulose filter paper and prepared for amplification after a quick purification.In this study,a published filter paper strip method was modified by sticking the filter paper on a polyvinyl chloride resin(PVC)sheet.This modified method is named EZ-D,for EASY DNA extraction.Compared with the original cetyl trimethylammonium bromide(CTAB)method,DNA extracted by EZ-D is more efficient in polymerase chain reaction(PCR)amplification due to the more stable performance of the EZ-D stick.The EZ-D method is also faster,easier,and cheaper.PCR analyses showed that DNA extracted from several types of plant tissues by EZ-D was appropriate for specific identification of biological samples.A regular PCR reaction can detect the EZ-D-extracted DNA template at concentration as low as 0.1 ng/μL.Evaluation of the EZ-D showed that DNA extracts could be successfully amplified by PCR reaction for DNA fragments up to 3000 bp in length and up to 80%in GC content.EZ-D was successfully used for DNA extraction from a variety of plant species and plant tissues.Moreover,when EZ-D was combined with the loop-mediated isothermal amplification(LAMP)method,DNA identification of biological samples could be achieved without the need for specialized equipment.As an optimized DNA purification method,EZ-D shows great advantages in application and can be used widely in laboratories where equipment is limited and rapid results are required.     

DNA’s new avatar as nanoscale construction material

DNA is fast taking on a new aspect utilizing it’s physical property of persistence length and chemical property of base pairing to build architectures in 1D, 2D and 3D. This field is called structural DNA nano-technology and is poised to revolutionize several areas ranging from materials science to cell biology.     

DNA序列的3D图形表示（英文）

本文介绍一种新的DNA序列的三维图形表示，它可以避免相应空间图形的交叉和重叠。该图形表示的好处还在于，它仅仅有两种需要计算的可能情况，而在其它的三维表示中，往往有三种需要计算的情况。究其应用，我们对两种可能产生的表示情况，通过计算十二种不同物种间编码序列对应的L/L矩阵产生的正规特征值，构造一个2-维向量来检测上述物种间的相似性与非相似性。     

灿烂甲酚蓝标记分光光度法测定核酸

研究了灿烂甲酚蓝与小牛胸腺DNA相互作用，提出了测定ctDNA的新的光度分析法。室温、pH8．1tris-HCl的条件下，ctDNA的加入使灿烂甲酚蓝在其最大吸收波长636nm处的吸光度明显下降，下降的程度与ctDNA的含量呈线性关系，ctDNA质量浓度在0～3．0μg／ml范围内与△A呈线性关系，线性回归方程为△A=0．0032 0．0984C(μg/ml）(r=0．9987)，方法的检出限（3σ／k)为0．125μg/ml。该方法具有仪器简单，快速，选择性好等特点，对合成样品中ctDNA测定，RSD％=1．5～1．9，回收率在101％～104％，结果令人满意。     

Effects of medium composition on the production of plasmid DNA vector potentially for human gene therapy

INTRODUCTION The difficulties associated with large-scaleproduction of biotherapeutics provide a constantchallenge to the biotechnology industry. FDA hadadded “therapeutic DNA plasmid vectors” to the listof well-characterized biotechnology product (DoHHs,1996), and gene therapy has moved rapidly fromlaboratory scale to clinical trials. It is urgent to de-velop new protocols to obtain high-quality plasmidswith high yields and minimal or no contamination ofRNA and chromosomal D…