高密度基因芯片探针布局方法

为了提高基因芯片制备质量和检测的准确性,提出两种基因芯片布局方法,一是分子印章凸点优化布局方法,另一种是基于探针杂交解链温度的梯度场布局方法。利用上述两种方法对所设计的高密度基因芯片进行控针布局实验,结果表明,第一种方法能够使制备基因芯片的分子印章上凸点均匀分布,解决误压印问题,从而提高基因芯片的制备质量;而第二种方法能够使基因芯片上的探针按照杂交解链温度有序地组织起来,从而提高基因芯片对碱基错配的辨别力。     

基于马尔可夫链的基因芯片特异性探针选择方法

对于基因表达芯片,特异性探针的选择是探针设计的重要环节,由于基因组序列数据量极大,不可能对每个候选探针都在全序列中进行特异性评价并进行取舍。对此问题,提出了一种采用马尔可夫链概率准则的探针特异性选择方法,即把基因组序列看作马尔可夫链,任何探针序列的互补序列作为它的一个子序列,都具有一定的出现概率,概率越小,越可能具有特异性。据此,选择其中概率最小的N个候选探针,能够大大减少进行特异性评价的探针数量,缩短探针设计的计算时间。对实际数据的测试结果表明,该方法选择的探针具有很高的特异性。     

纯化探针降低基因芯片杂交结果的背景

研究探针的纯化对基因芯片杂交结果的影响。将乙醇沉淀的探针和用DNA纯化试剂盒纯化的探针分别与基因芯片交,在同等条件下进行杂交后清洗和芯片扫描检测。结果表明,纯化的探针与基因芯片杂交结果的背景低,而未纯化的探针背景强,阳性信号界限比较模糊。运用基因芯片进行基因表达谱研究,要求杂交检测的结果必须低背景。探针的纯化是影响芯片杂交结果的一个重要因素。     

炭疽芽胞杆菌基因芯片探针文库的构建

为制备炭疽芽胞杆菌的基因芯片探针文库,以炭疽芽胞杆菌毒素质粒pX01和荚膜质粒pX02为原材料,用Sau3A I酶切pX01和pX02质粒DNA,Taq DNA聚合酶72℃补平加A,经AT克隆,PCR初步鉴定筛选出炭疽质粒片段的阳性克隆．DNA自动分析仪对克隆片段进行序列测定;用生物信息学方法对其片段进行同源性分析;并将克隆的探针打印于玻片上,制备成炭疽芽胞杆茵基因芯片,与炭疽杆茵质粒DNA样品进行初步芯片杂交的实验,杂交实验的阳性率达到了90％以上,证明大部分克隆探针属于炭疽芽胞杆菌．炭疽芽胞杆菌基因芯片探针文库的构建为基因芯片探针的制备摸索出一条简便、高效、可行的方法．     

用巢式PCR方法制备基因芯片的探针

制备出高纯度的探针,用于诊断基因芯片的打印。采用巢式PCR技术,M13作为外侧引物并自行设计内侧引物,扩增克隆在T载体上的基因片段。可制备出成分单一,上下游仅含19bp和20bp的短载体序列的探针,能使打印出的芯片得到较好的杂交效果。该法充分利用巢式PCR的优点,对制备探针的方法进行改进,且简便快速,能得到更高质量的探针,满足打印芯片的要求。     

基于组合探针识别的大规模细菌分类16 S rRNA基因芯片设计

随着16 S rRNA序列资源的不断丰富,以及寡核苷酸微阵列基因芯片技术的不断进步,检测复杂微生物菌落中的微生物种群构成成为可能．现有的序列特异性探针设计算法缺乏足够的覆盖度、灵活性以及效率,不能满足大规模细菌检测基因芯片的设计要求．很多组特异性探针设计算法的思路多局限于针对某个目标序列组设计唯一的组特异性探针．在很多应用场合,设计单个探针检测组内所有目标序列的目标是很难达到的．因此,设计多个探针通过组合方式进行检测是很有必要的．每个探针能特异性地检测组内一部分目标序列,通过组合就能提高覆盖率．然而,在所有可能的探针组合中找到一个优化的探针组合是很耗时的．提出了一个可行的基于相对熵和遗传算法的组合探针设计算法．     

基于纳米金复合探针的基因芯片膜转印检测法

建立了一种基于纳米金复合探针的基因芯片膜转印核酸检测新方法。首先,用纳米金颗粒同时标记检测探针P2和两种长短不同且生物素化的信号探针 (T10,T40),其中检测探针与靶DNA 5￠端互补,两种信号探针起信号放大作用。当靶DNA分子存在时,芯片表面捕捉探针P1 (与靶DNA分子3￠端互补) 通过碱基互补配对原则结合靶DNA分子,将其固定于芯片上,同时检测探针通过与靶DNA 5￠端互补配对将纳米金复合探针结合于芯片表面,结果在芯片表面形成“三明治”结构,后通过链霉亲和素-生物素反应,使芯片表面对应有靶DNA分子的部位结合上碱性磷酸酶,最后利用BCIP/NBT显色系统使芯片表面信号结果镜面转印至尼龙膜表面。当检测探针和信号探针摩尔比为1∶10,T10和T40摩尔比为9:1时可以检测1 pmol/L合成靶DNA分子或0.23 pmol/L结核分枝杆菌16S rDNA PCR扩增产物,检测结果通过普通的光学扫描仪读取或肉眼直接判读信号有无。本芯片检测系统灵敏度高,操作方法简单、快速,不需要特殊仪器设备,在生物分子的检测方面具有较高的应用价值。     

制备炭疽芽胞杆菌检测基因芯片的初步研究

建立制备炭疽芽胞杆菌检测基因芯片的技术,并探讨研制检测炭疽芽胞杆菌基因芯片的方法。酶切炭疽芽胞杆菌的毒素质粒和荚膜质粒,通过建立质粒DNA文库的方法获取探针,并打印在经过氨基化修饰的玻片上,制成用于炭疽芽胞杆菌检测的基因芯片。收集了290个阳性克隆探针,制备了检测炭疽芽胞杆菌的基因芯片。提取炭疽芽胞杆菌质粒DNA与基因芯片杂交,经ScanArray Lite芯片阅读仪扫描得到初步的杂交荧光图像。通过分析探针的杂交信号初步筛选出273个基因片段作为芯片下一步研究的探针。     

基因表达芯片探针选择的一种有效方法

为了减少基因表达芯片探针选择的计算量,采用最大共有序列准则大大减少了需要计算的候选探针数量,并通过不断扩大进行计算的探针数目保证探针选择的效果．结果表明该方法是十分有效的,探针选择的结果也是令人满意的．     

用于寡核苷酸探针设计的ARB软件

探针设计是制备高质量基因芯片的重中之重。ARB软件是用于设计系统发育芯片(Phylo Chip)探针的主要软件,然而由于安装困难、相关中文文章较少等原因,阻碍了其在国内的广泛使用。本文详细介绍了ARB软件的安装方法、探针设计及其他功能。这将有助于用户快速使用ARB软件进行探针设计,促进系统发育芯片的发展及其在各领域的应用。     

Randomized probe selection algorithm for microarray design

DNA microarray technology, originally developed to measure the level of gene expression, has become one of the most widely used tools in genomic study. The crux of microarray design lies in how to select a unique probe that distinguishes a given genomic sequence from other sequences. Due to its significance, probe selection attracts a lot of attention. Various probe selection algorithms have been developed in recent years. Good probe selection algorithms should produce a small number of candidate probes. Efficiency is also crucial because the data involved are usually huge. Most existing algorithms are usually not sufficiently selective and quite a large number of probes are returned. We propose a new direction to tackle the problem and give an efficient algorithm based on randomization to select a small set of probes and demonstrate that such a small set of probes is sufficient to distinguish each sequence from all the other sequences. Based on the algorithm, we have developed probe selection software RandPS, which runs efficiently in practice. The software is available on our website (http://www.csc.liv.ac.uk/ approximately cindy/RandPS/RandPS.htm). We test our algorithm via experiments on different genomes (Escherichia coli, Saccharamyces cerevisiae, etc.) and our algorithm is able to output unique probes for most of the genes efficiently. The other genes can be identified by a combination of at most two probes.     

基因芯片制备方法研究进展

基因芯片是融微电子学、生命科学和物理学为一体的技术,目前广泛应用于疾病的基因诊断、基因表达研究、基因组研究、发现新基因以及病原体的诊断,具有广阔的应用前景。基因芯片的制备主要可分为原位合成、合成后交联二种方法。本文综述了基因芯片的制备方法分析了各自的优缺点。     

Comparison of commercial probe labeling kits for microarray: towards quality assurance and consistency of reactions

Microarray technology is readily available to scientists interested in gene expression. Commensurate with this availability is the growing market in accessory products offering convenience but potentially variable performance. Here we evaluate seven commercial kits for probe labeling against a human apoptosis oligonucleotide array. All kits were found to label probes successfully using the manufacturers' instructions. The Stratagene Fairplay Microarray Labeling Kit was the most sensitive, with an overall call rate of 74% and the lowest rate of indeterminant calls for the HEK and HepG2 cell lines. The Invitrogen SuperScript Indirect cDNA Labeling System showed the most reproducible gene expression pattern and the least technical variation, both in terms of signal strength and between replicates on each array. The Promega Pronto! Plus System showed the least dye bias however, a higher level of variation between replicates was observed. Pairwise comparisons revealed that the Promega Pronto! Plus System and Invitrogen SuperScript Indirect cDNA Labeling System had the most similarity in their patterns of gene expression. Results obtained suggest variability in the performance of commercial kits between different manufacturers. This study supports the need to conduct comparative evaluations of commercial microarray probe labeling kits and the need for validation prior to use.     

SARS病毒再测序DNA微阵列的探针设计

探针设计是SARS病毒再测序DNA微阵列制作的关键步骤,为了保证探针的杂交条件尽可能一致,采用了作者提出的两种等长变覆盖的探针设计方法,即基于Tm距离的算法和遗传算法。针对SAILS病毒基因组中的两段特异序列设计了一组探针,并与等长移位法和变长变覆盖法的设计结果进行了比较。等长变覆盖法得到的探针集在探针长度一致的情况下,探针的Tm值有较小的标准差和变化范围。结果表明,等长变覆盖法得到的探针具有更好的杂交条件一致性。     

地高辛标记探针检测重组人干扰素β_(1b)中DNA残留量

为检测注射用重组人干扰素β1b半成品中外源性DNA残留量,以重组人干扰素β1b工程菌基因组DNA为模板,用地高辛标记探针,并以此探针进行点杂交。结果证明,该方法检测灵敏度较好,特异性较强,操作较安全简便,可用于重组人干扰素β1b制备过程中的质量监控及半成品的检定。     

四川山鹧鸪的转录组组装和注释

四川山鹧鸪Arborophila rufipectus是中国特有的珍稀濒危鸟类.本研究对1只成年雄性四川山鹧鸪个体的心脏、肝脏和肾脏进行了转录组测序、组装和注释.其原始序列过滤后分别产生了5.70 G、4.60 G和5.16 G数据.286661条转录本经过Trinity组装并去掉冗余后共得到234488个基因.BUS...     

Genes Selection Comparative Study in Microarray Data Analysis

In response to the rapid development of DNA Microarray Technologies, many differentially expressed genes selection algorithms have been developed, and different comparison studies of these algorithms have been done. However, it is not clear how these methods compare with each other, especially when we used different developments tools. Here, we considered three commonly used differentially expressed genes selection approaches, namely: Fold Change, T-test and SAM, using Bioinformatics Matlab Toolbox and R/BioConductor. We used two datasets, issued from the affymetrix technology, to present results of used methods and software''s in gene selection process. The results, in terms of sensitivity and specificity, indicate that the behavior of SAM is better compared to Fold Change and T-test using R/BioConductor. While, no practical differences were observed between the three gene selection methods when using Bioinformatics Matlab Toolbox. In face of our result, the ROC curve shows that: on the one hand R/BioConductor using SAM is favored for microarray selection compared to the other methods. And, on the other hand, results of the three studied gene selection methods using Bioinformatics Matlab Toolbox are still comparable for the two datasets used.