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Microarray analysis techniques

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198:, can also be applied. Given the number of distance measures available and their influence in the clustering algorithm results, several studies have compared and evaluated different distance measures for the clustering of microarray data, considering their intrinsic properties and robustness to noise. After calculation of the initial distance matrix, the hierarchical clustering algorithm either (A) joins iteratively the two closest clusters starting from single data points (agglomerative, bottom-up approach, which is fairly more commonly used), or (B) partitions clusters iteratively starting from the complete set (divisive, top-down approach). After each step, a new distance matrix between the newly formed clusters and the other clusters is recalculated. Hierarchical cluster analysis methods include: 65: 52: 17: 144:
observation, since the point of performing experiments has to do with predicting general behavior. The MAQC group recommends using a fold change assessment plus a non-stringent p-value cutoff, further pointing out that changes in the background correction and scaling process have only a minimal impact on the rank order of fold change differences, but a substantial impact on p-values.
307:. Protein complex enrichment analysis tool (COMPLEAT) provides similar enrichment analysis at the level of protein complexes. The tool can identify the dynamic protein complex regulation under different condition or time points. Related system, PAINT and SCOPE performs a statistical analysis on gene promoter regions, identifying over and under representation of previously identified 279: 329: 119: 971:(t) are specified to guarantee genes called significant change at least a pre-specified amount. This means that the absolute value of the average expression levels of a gene under each of two conditions must be greater than the fold change (t) to be called positive and less than the inverse of the fold change (t) to be called negative. 964: 39: – in a single experiment. Such experiments can generate very large amounts of data, allowing researchers to assess the overall state of a cell or organism. Data in such large quantities is difficult – if not impossible – to analyze without the help of computer programs. 103:
Raw Affy data contains about twenty probes for the same RNA target. Half of these are "mismatch spots", which do not precisely match the target sequence. These can theoretically measure the amount of nonspecific binding for a given target. Robust Multi-array Average (RMA) is a normalization approach
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response elements. Another statistical analysis tool is Rank Sum Statistics for Gene Set Collections (RssGsc), which uses rank sum probability distribution functions to find gene sets that explain experimental data. A further approach is contextual meta-analysis, i.e. finding out how a gene cluster
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for Robust Microarray Summarization (FARMS) is a model-based technique for summarizing array data at perfect match probe level. It is based on a factor analysis model for which a Bayesian maximum a posteriori method optimizes the model parameters under the assumption of Gaussian measurement noise.
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Microarray data analysis is the final step in reading and processing data produced by a microarray chip. Samples undergo various processes including purification and scanning using the microchip, which then produces a large amount of data that requires processing via computer software. It involves
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Visual identification of local artifacts, such as printing or washing defects, may likewise suggest the removal of individual spots. This can take a substantial amount of time depending on the quality of array manufacture. In addition, some procedures call for the elimination of all spots with an
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Depending on the type of array, signal related to nonspecific binding of the fluorophore can be subtracted to achieve better results. One approach involves subtracting the average signal intensity of the area between spots. A variety of tools for background correction and further analysis are
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or other mechanisms that take both effect size and variability into account. Curiously, the p-values associated with particular genes do not reproduce well between replicate experiments, and lists generated by straight fold change perform much better. This represents an extremely important
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Many strategies exist to identify array probes that show an unusual level of over-expression or under-expression. The simplest one is to call "significant" any probe that differs by an average of at least twofold between treatment groups. More sophisticated approaches are often related to
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several distinct steps, as outlined in the image below. Changing any one of the steps will change the outcome of the analysis, so the MAQC Project was created to identify a set of standard strategies. Companies exist that use the MAQC protocols to perform a complete analysis.
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Comparing two different arrays or two different samples hybridized to the same array generally involves making adjustments for systematic errors introduced by differences in procedures and dye intensity effects. Dye normalization for two color arrays is often achieved by
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Specialized software tools for statistical analysis to determine the extent of over- or under-expression of a gene in a microarray experiment relative to a reference state have also been developed to aid in identifying genes or gene sets associated with particular
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Blocks are batches of microarrays; for example for eight samples split into two groups (control and affected) there are 4!=24 permutations for each block and the total number of permutations is (24)(24)= 576. A minimum of 1000 permutations are
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SAM is run as an Excel Add-In, and the SAM Plot Controller allows Customization of the False Discovery Rate and Delta, while the SAM Plot and SAM Output functionality generate a List of Significant Genes, Delta Table, and Assessment of Sample
358:, it is now possible to measure the expression of thousands of genes in a single hybridization experiment. The data generated is considerable, and a method for sorting out what is significant and what isn't is essential. SAM is distributed by 1060:
Entire arrays may have obvious flaws detectable by visual inspection, pairwise comparisons to arrays in the same experimental group, or by analysis of RNA degradation. Results may improve by removing these arrays from the analysis entirely.
299:-style statistic to identify groups of genes that are regulated together. This third-party statistics package offers the user information on the genes or gene sets of interest, including links to entries in databases such as NCBI's 545:
SAM calculates a test statistic for relative difference in gene expression based on permutation analysis of expression data and calculates a false discovery rate. The principal calculations of the program are illustrated below.
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Commercial systems for gene network analysis such as Ingenuity and Pathway studio create visual representations of differentially expressed genes based on current scientific literature. Non-commercial tools such as FunRich,
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Adjust the Delta tuning parameter to get a significant # of genes along with an acceptable false discovery rate (FDR)) and Assess Sample Size by calculating the mean difference in expression in the SAM Plot
96:. LIMMA provides a set of tools for background correction and scaling, as well as an option to average on-slide duplicate spots. A common method for evaluating how well normalized an array is, is to plot an 216:
Different studies have already shown empirically that the Single linkage clustering algorithm produces poor results when employed to gene expression microarray data and thus should be avoided.
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Jaskowiak, Pablo A.; Campello, Ricardo J.G.B.; Costa, Ivan G. (2013). "Proximity Measures for Clustering Gene Expression Microarray Data: A Validation Methodology and a Comparative Analysis".
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of the data are used to determine if the expression of any gene is significant related to the response. The use of permutation-based analysis accounts for correlations in genes and avoids
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also aid in organizing and visualizing gene network data procured from one or several microarray experiments. A wide variety of microarray analysis tools are available through
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is a public tool to perform contextual meta-analysis across contexts such as anatomical parts, stages of development, and response to diseases, chemicals, stresses, and
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Call each gene significant if the absolute value of the test statistic for that gene minus the mean test statistic for that gene is greater than a stated threshold
2177:"Integration of statistical inference methods and a novel control measure to improve sensitivity and specificity of data analysis in expression profiling studies" 536:— no explicit response parameter is specified; the user specifies eigengene (principal component) of the expression data and treats it as a quantitative response 1075: 2232:<Zhang, S. (2007). "A comprehensive evaluation of SAM, the SAM R-package and a simple modification to improve its performance." BMC Bioinformatics 8: 230. 238:. Thus the purpose of K-means clustering is to classify data based on similar expression. K-means clustering algorithm and some of its variants (including 115:
The current Affymetrix MAS5 algorithm, which uses both perfect match and mismatch probes, continues to enjoy popularity and do well in head to head tests.
2543: 275:. The frequently cited SAM module and other microarray tools are available through Stanford University. Another set is available from Harvard and MIT. 242:) have been shown to produce good results for gene expression data (at least better than hierarchical clustering methods). Empirical comparisons of 183: 35:, which allow researchers to investigate the expression state of a large number of genes – in many cases, an organism's entire 1071: 2609: 1637:
Guo L, Lobenhofer EK, Wang C, et al. (2006). "Rat toxicogenomic study reveals analytical consistency across microarray platforms".
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Chu, G., Narasimhan, B, Tibshirani, R, Tusher, V. "SAM "Significance Analysis of Microarrays" Users Guide and technical document."
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According to the Affycomp benchmark FARMS outperformed all other summarizations methods with respect to sensitivity and specificity.
1896: 1227: 2036: 1590:"The MicroArray Quality Control (MAQC) project shows inter- and intraplatform reproducibility of gene expression measurements" 1689: 112:, also part of RMA, is one sensible approach to normalize a batch of arrays in order to make further comparisons meaningful. 1101: 504:— measurement units are different in the two groups; e.g. control and treatment groups with samples from different patients 234:
groups. Grouping is done by minimizing the sum of the squares of distances between the data and the corresponding cluster
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Dinu, I. P.; JD; Mueller, T; Liu, Q; Adewale, AJ; Jhangri, GS; Einecke, G; Famulski, KS; Halloran, P; Yasui, Y. (2007).
510:— same experimental units are measured in the two groups; e.g. samples before and after treatment from the same patients 2640: 384:, which measures the strength of the relationship between gene expression and a response variable. This analysis uses 2620: 1807:
de Souto, Marcilio C. P.; Costa, Ivan G.; de Araujo, Daniel S. A.; Ludermir, Teresa B.; Schliep, Alexander (2008).
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Positive gene set — higher expression of most genes in the gene set correlates with higher values of the phenotype
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Negative gene set — lower expression of most genes in the gene set correlates with higher values of the phenotype
392:. The response variable describes and groups the data based on experimental conditions. In this method, repeated 108:. The median polish algorithm, although robust, behaves differently depending on the number of samples analyzed. 1329: 264: 2061: 2362:"Comparison and evaluation of methods for generating differentially expressed gene lists from microarray data" 1399:"A comparison of normalization methods for high density oligonucleotide array data based on variance and bias" 397: 2614: 2547: 1491:"Comparative analysis of microarray normalization procedures: effects on reverse engineering gene networks" 1136:"Gene set enrichment analysis: A knowledge-based approach for interpreting genome-wide expression profiles" 400:
assumptions about the distribution of individual genes. This is an advantage over other techniques (e.g.,
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that does not take advantage of these mismatch spots but still must summarize the perfect matches through
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the number of permutations is set by the user when imputing correct values for the data set to run SAM
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Example of an approximately 40,000 probe spotted oligo microarray with enlarged inset to show detail.
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ArrayExplorer - Compare microarray side by side to find the one that best suits your research needs
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Can work with blocked design for when treatments are applied within different batches of arrays
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Clustering is a data mining technique used to group genes having similar expression patterns.
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experiments — DNA microarray with oligo and cDNA primers, SNP arrays, protein arrays, etc.
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of the data. MA plots can be produced using programs and languages such as R and MATLAB.
2267: 1356:; Hobbs, B; Collin, F; Beazer-Barclay, YD; Antonellis, KJ; Scherf, U; Speed, TP (2003). 250:, hierarchical methods and, different distance measures can be found in the literature. 2439: 2412: 2388: 2361: 2337: 2310: 2013: 1989:"Protein Complex-Based Analysis Framework for High-Throughput Data Sets. 6, rs5 (2013)" 1835: 1808: 1781: 1754: 1730: 1662: 1614: 1589: 1466: 1439: 1306: 1273: 1162: 1135: 296: 230:
K-means clustering is an algorithm for grouping genes or samples based on pattern into
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Data from Oligo or cDNA arrays, SNP array, protein arrays, etc. can be utilized in SAM
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Example of FunRich tool output. Image shows the result of comparing 4 different genes.
2600: 2576: 2485: 2464:"Simpleaffy: a BioConductor package for Affymetrix Quality Control and data analysis" 2444: 2393: 2342: 2291: 2286: 2248: 2198: 2018: 1840: 1786: 1722: 1685: 1654: 1619: 1553: 1512: 1471: 1420: 1379: 1311: 1293: 1207: 1167: 343: 2480: 2463: 2413:"Considerations when using the significance analysis of microarrays (SAM) algorithm" 1548: 1531: 1507: 1490: 1374: 1357: 2475: 2434: 2424: 2383: 2373: 2332: 2322: 2281: 2271: 2188: 2008: 2000: 1830: 1820: 1776: 1766: 1714: 1666: 1646: 1609: 1601: 1543: 1502: 1461: 1451: 1410: 1369: 1301: 1285: 1157: 1147: 191: 93: 1734: 2249:"Significance analysis of microarrays applied to the ionizing radiation response" 2147: 1330:"Create intensity versus ratio scatter plot of microarray data - MATLAB mairplot" 1106: 351: 179: 126: 2503: 178:
clusters. Hierarchical clustering consists of two separate phases. Initially, a
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List Differentially Expressed Genes (Positively and Negatively Expressed Genes)
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SAM identifies statistically significant genes by carrying out gene specific
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Uses data permutation to estimates False Discovery Rate for multiple testing
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for academic and non-academic users after completion of a registration step.
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Bioinformatics and computational biology solutions using R and Bioconductor
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Estimate the false discovery rate based on expected versus observed values
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Gatto, Laurent; Breckels, Lisa M.; Naake, Thomas; Gibb, Sebastian (2015).
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FARMS - Factor Analysis for Robust Microarray Summarization, an R package
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ArrayMining.net - web-application for online analysis of microarray data
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Reports local false discovery rate (the FDR for genes having a similar d
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containing all the pairwise distances between the genes is calculated.
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Hierarchical clustering is a statistical method for finding relatively
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are used in interpreting the data generated from experiments on DNA (
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are often used as dissimilarity estimates, but other methods, like
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Can adjust threshold determining number of gene called significant
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For each permutation compute the ordered null (unaffected) scores
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Jaskowiak, Pablo A; Campello, Ricardo JGB; Costa, Ivan G (2014).
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IEEE/ACM Transactions on Computational Biology and Bioinformatics
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Plot the ordered test statistic against the expected null scores
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constant is chosen to minimize the coefficient of variation of
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Vinayagam A, Hu Y, Kulkarni M, Roesel C, et al. (2013).
1809:"Clustering cancer gene expression data: a comparative study" 1571: 408:), which assume equal variance and/or independence of genes. 401: 323: 206: 1876: 1532:"A new summarization method for affymetrix probe level data" 1185:
Dr. Leming Shi, National Center for Toxicological Research.
1967: 1396: 1274:"Visualization of proteomics data using R and Bioconductor" 2311:"Improving gene set analysis of microarray data by SAM-GS" 1921: 1529: 550: 492:— tests whether the mean gene expression differs from zero 278: 122:
Flowchart showing how the MAS5 algorithm by Agilent works.
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GeneChip® Expression Analysis-Data Analysis Fundamentals
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Subramanian A, Tamayo P, Mootha VK, et al. (2005).
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Input Expression Analysis in Microsoft Excel — see below
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expression value below a certain intensity threshold.
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Bolstad BM, Irizarry RA, Astrand M, Speed TP (2003).
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Identification of significant differential expression
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Complete linkage (maximum method, furthest neighbor)
2247:Tusher, V. G.; Tibshirani, R.; et al. (2001). 160:are widely used techniques in microarray analysis. 1253:"LIMMA Library: Linear Models for Microarray Data" 958: 354:are statistically significant. With the advent of 1636: 1027:Correlates expression data to clinical parameters 202:Single linkage (minimum method, nearest neighbor) 2627: 2583:StatsArray - Online Microarray Analysis Services 2359: 2308: 2246: 1748: 1746: 1744: 1438:Giorgi FM, Bolger AM, Lohse M, Usadel B (2010). 312:responds to a variety of experimental contexts. 86: 2256:Proceedings of the National Academy of Sciences 1489:Lim WK, Wang K, Lefebvre C, Califano A (2007). 581:is equal to the expression levels (x) for gene 2595:FunRich - Perform gene set enrichment analysis 2410: 1588:Shi L, Reid LH, Jones WD, et al. (2006). 1530:Hochreiter S, Clevert DA, Obermayer K (2006). 1741: 1698: 1684:. New York: Springer Science+Business Media. 1208:"GenUs BioSystems - Services - Data Analysis" 978:Order test statistics according to magnitude 458:are calculated based on the number of samples 55:The steps required in a microarray experiment 2461: 1802: 1800: 1587: 2107:"SAM: Significance Analysis of Microarrays" 1187:"MicroArray Quality Control (MAQC) Project" 303:and curated databases such as Biocarta and 342:, established in 2001 by Virginia Tusher, 336:Significance analysis of microarrays (SAM) 324:Significance analysis of microarrays (SAM) 163: 69:National Center for Toxicological Research 2479: 2438: 2428: 2387: 2377: 2360:Jeffery, I. H.; DG; Culhane, AC. (2006). 2336: 2326: 2285: 2275: 2192: 2012: 1922:"FunRich: Functional Enrichment Analysis" 1834: 1824: 1797: 1780: 1770: 1679: 1673: 1613: 1547: 1506: 1465: 1455: 1414: 1373: 1305: 1161: 1151: 1064: 444:SAM is available for download online at 327: 291:. One such method of analysis, known as 277: 117: 63: 50: 15: 2504:"J. Craig Venter Institute -- Software" 2411:Larsson, O. W. C; Timmons, JA. (2005). 2175:Zang, S.; Guo, R.; et al. (2007). 2174: 1680:Gentleman, Robert; et al. (2005). 446:http://www-stat.stanford.edu/~tibs/SAM/ 75:Most microarray manufacturers, such as 2628: 2621:Duke data_analysis_fundamentals_manual 1968:"BioCarta - Charting Pathways of Life" 253: 2242: 2240: 2238: 2228: 2226: 2224: 2222: 2220: 2218: 2216: 2214: 2212: 2170: 2168: 2166: 2164: 2162: 2160: 2158: 2156: 2154: 2142: 2140: 2138: 2136: 2134: 2132: 2130: 2128: 2126: 1583: 1581: 350:, for determining whether changes in 219: 2601:Comparative Transcriptomics Analysis 2544:"Ocimum Biosolutions | Genowiz" 1129: 1127: 1102:Significance analysis of microarrays 1051:Error correction and quality control 1030:Correlates expression data with time 974:The SAM algorithm can be stated as: 427:Run SAM as a Microsoft Excel Add-Ins 1189:. U.S. Food and Drug Administration 474: 13: 2404: 2353: 2302: 2235: 2209: 2151: 2123: 1897:"Ariadne Genomics: Pathway Studio" 1578: 1055: 949: 946: 943: 940: 937: 934: 931: 928: 925: 922: 919: 913: 910: 907: 904: 901: 898: 892: 889: 886: 883: 880: 874: 871: 865: 862: 859: 856: 853: 850: 845: 842: 839: 836: 833: 827: 824: 821: 818: 815: 812: 806: 803: 800: 797: 794: 791: 788: 782: 779: 773: 767: 764: 755: 752: 749: 746: 743: 740: 737: 734: 731: 728: 720: 717: 706: 703: 694: 691: 688: 685: 682: 679: 667: 664: 661: 652: 649: 646: 643: 637: 634: 631: 628: 625: 622: 619: 616: 613: 607: 604: 601: 598: 595: 486:— real-valued (such as heart rate) 388:, since the data may not follow a 14: 2652: 2605:Reference Module in Life Sciences 2565: 2181:Journal of Biomedical Informatics 1124: 1081: 585:under y experimental conditions. 411: 71:scientist reviews microarray data 1228:"Agilent | DNA Microarrays" 554: 549: 2536: 2516: 2496: 2455: 2099: 2079: 2054: 2029: 1980: 1960: 1940: 1934: 1914: 1889: 1869: 1851: 1630: 1564: 1523: 1482: 1431: 1416:10.1093/bioinformatics/19.2.185 1018: 42: 2524:"Agilent | GeneSpring GX" 1390: 1346: 1322: 1265: 1245: 1220: 1200: 1178: 1070:available from TIGR, Agilent ( 758: 700: 670: 658: 438: 25:Microarray analysis techniques 1: 2481:10.1093/bioinformatics/bti605 2462:Wilson CL, Miller CJ (2005). 1549:10.1093/bioinformatics/btl033 1508:10.1093/bioinformatics/btm201 1375:10.1093/biostatistics/4.2.249 1117: 1040:as that gene) and miss rates 147: 87:Aggregation and normalization 59: 1140:Proc. Natl. Acad. Sci. U.S.A 540: 7: 1090: 498:— two sets of measurements 10: 2657: 1772:10.1186/1471-2105-15-S2-S2 223: 167: 2641:Bioinformatics algorithms 2610:SAM download instructions 2194:10.1016/j.jbi.2007.01.002 2005:10.1126/scisignal.2003629 994: 386:non-parametric statistics 373:and computes a statistic 1457:10.1186/1471-2105-11-553 295:Analysis (GSEA), uses a 2430:10.1186/1471-2105-6-129 2379:10.1186/1471-2105-7-359 2328:10.1186/1471-2105-8-242 1826:10.1186/1471-2105-9-497 1153:10.1073/pnas.0506580102 170:Hierarchical clustering 164:Hierarchical clustering 154:Hierarchical clustering 2277:10.1073/pnas.091062498 1290:10.1002/pmic.201400392 1000:Significant gene sets 960: 332: 283: 273:R programming language 188:Spearman's correlation 123: 110:Quantile normalization 72: 56: 21: 2111:tibshirani.su.domains 1065:Background correction 961: 340:statistical technique 331: 281: 184:Pearson's correlation 121: 67: 54: 19: 1234:on December 22, 2007 1097:Microarray databases 1076:Ocimum Bio Solutions 591: 309:transcription factor 31:), RNA, and protein 2268:2001PNAS...98.5116G 1877:"Ingenuity Systems" 1719:10.1109/TCBB.2013.9 461:Block Permutations 390:normal distribution 360:Stanford University 293:Gene Set Enrichment 254:Pattern recognition 2417:BMC Bioinformatics 2366:BMC Bioinformatics 2315:BMC Bioinformatics 1948:"Software - Broad" 1813:BMC Bioinformatics 1759:BMC Bioinformatics 1444:BMC Bioinformatics 956: 333: 297:Kolmogorov-Smirnov 284: 226:k-means clustering 220:K-means clustering 196:Euclidean distance 192:Manhattan distance 158:k-means clustering 124: 73: 57: 29:Gene chip analysis 22: 1691:978-0-387-29362-2 953: 918: 897: 879: 870: 832: 811: 787: 778: 772: 763: 727: 711: 699: 657: 642: 612: 534:Pattern discovery 344:Robert Tibshirani 205:Average linkage ( 2648: 2559: 2558: 2556: 2555: 2546:. 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Biotechnol 1586: 1579: 1570: 1569: 1565: 1528: 1524: 1487: 1483: 1436: 1432: 1395: 1391: 1351: 1347: 1338: 1336: 1328: 1327: 1323: 1270: 1266: 1257: 1255: 1251: 1250: 1246: 1237: 1235: 1226: 1225: 1221: 1212: 1210: 1206: 1205: 1201: 1192: 1190: 1183: 1179: 1132: 1125: 1120: 1107:Transcriptomics 1093: 1084: 1067: 1058: 1056:Quality control 1053: 1039: 1021: 1012: 1006: 997: 849: 716: 712: 678: 676: 594: 592: 589: 588: 580: 573: 567: 543: 477: 441: 414: 378: 356:DNA microarrays 352:gene expression 326: 271:written in the 256: 228: 222: 180:distance matrix 172: 166: 150: 136: 127:Factor analysis 89: 62: 45: 12: 11: 5: 2654: 2644: 2643: 2638: 2624: 2623: 2618: 2612: 2607: 2598: 2592: 2586: 2580: 2574: 2567: 2566:External links 2564: 2561: 2560: 2535: 2515: 2495: 2474:(18): 3683–5. 2468:Bioinformatics 2454: 2403: 2352: 2301: 2234: 2208: 2187:(5): 552–560. 2150: 2122: 2098: 2078: 2053: 2028: 1979: 1959: 1939: 1933: 1913: 1888: 1868: 1850: 1796: 1740: 1713:(4): 845–857. 1697: 1690: 1672: 1629: 1600:(9): 1151–61. 1577: 1563: 1542:(8): 943–949. 1536:Bioinformatics 1522: 1501:(13): i282–8. 1495:Bioinformatics 1481: 1430: 1403:Bioinformatics 1389: 1345: 1321: 1264: 1244: 1219: 1199: 1177: 1122: 1121: 1119: 1116: 1115: 1114: 1109: 1104: 1099: 1092: 1089: 1083: 1082:Spot filtering 1080: 1066: 1063: 1057: 1054: 1052: 1049: 1048: 1047: 1044: 1041: 1037: 1034: 1031: 1028: 1025: 1020: 1017: 1016: 1015: 1014: 1013: 1010: 1007: 1004: 996: 993: 992: 991: 988: 985: 982: 979: 951: 948: 945: 942: 939: 936: 933: 930: 927: 924: 921: 915: 912: 909: 906: 903: 900: 894: 891: 888: 885: 882: 876: 873: 867: 864: 861: 858: 855: 852: 847: 844: 841: 838: 835: 829: 826: 823: 820: 817: 814: 808: 805: 802: 799: 796: 793: 790: 784: 781: 775: 769: 766: 760: 757: 754: 751: 748: 745: 742: 739: 736: 733: 730: 722: 719: 715: 708: 705: 702: 696: 693: 690: 687: 684: 681: 675: 672: 669: 666: 663: 660: 654: 651: 648: 645: 639: 636: 633: 630: 627: 624: 621: 618: 615: 609: 606: 603: 600: 597: 576: 571: 565: 542: 539: 538: 537: 531: 525: 519: 513: 512: 511: 505: 493: 487: 476: 473: 469: 468: 467: 466: 459: 453: 449: 440: 437: 436: 435: 432: 428: 425: 422: 413: 412:Basic protocol 410: 380:for each gene 376: 325: 322: 314:Genevestigator 255: 252: 224:Main article: 221: 218: 214: 213: 210: 203: 168:Main article: 165: 162: 149: 146: 135: 132: 88: 85: 61: 58: 44: 41: 9: 6: 4: 3: 2: 2653: 2642: 2639: 2637: 2634: 2633: 2631: 2622: 2619: 2616: 2613: 2611: 2608: 2606: 2602: 2599: 2596: 2593: 2590: 2587: 2584: 2581: 2578: 2575: 2573: 2570: 2569: 2550:on 2009-11-24 2549: 2545: 2539: 2525: 2519: 2505: 2499: 2491: 2487: 2482: 2477: 2473: 2469: 2465: 2458: 2450: 2446: 2441: 2436: 2431: 2426: 2422: 2418: 2414: 2407: 2399: 2395: 2390: 2385: 2380: 2375: 2371: 2367: 2363: 2356: 2348: 2344: 2339: 2334: 2329: 2324: 2320: 2316: 2312: 2305: 2297: 2293: 2288: 2283: 2278: 2273: 2269: 2265: 2261: 2257: 2250: 2243: 2241: 2239: 2229: 2227: 2225: 2223: 2221: 2219: 2217: 2215: 2213: 2204: 2200: 2195: 2190: 2186: 2182: 2178: 2171: 2169: 2167: 2165: 2163: 2161: 2159: 2157: 2155: 2148: 2143: 2141: 2139: 2137: 2135: 2133: 2131: 2129: 2127: 2112: 2108: 2102: 2088: 2082: 2068:on 2011-08-17 2067: 2063: 2057: 2043:on 2007-07-05 2042: 2038: 2032: 2024: 2020: 2015: 2010: 2006: 2002: 1998: 1994: 1990: 1983: 1969: 1963: 1949: 1943: 1937: 1923: 1917: 1903:on 2007-12-30 1902: 1898: 1892: 1878: 1872: 1864: 1860: 1854: 1846: 1842: 1837: 1832: 1827: 1822: 1818: 1814: 1810: 1803: 1801: 1792: 1788: 1783: 1778: 1773: 1768: 1764: 1760: 1756: 1749: 1747: 1745: 1736: 1732: 1728: 1724: 1720: 1716: 1712: 1708: 1701: 1693: 1687: 1683: 1676: 1668: 1664: 1660: 1656: 1652: 1648: 1645:(9): 1162–9. 1644: 1640: 1633: 1625: 1621: 1616: 1611: 1607: 1603: 1599: 1595: 1591: 1584: 1582: 1573: 1567: 1559: 1555: 1550: 1545: 1541: 1537: 1533: 1526: 1518: 1514: 1509: 1504: 1500: 1496: 1492: 1485: 1477: 1473: 1468: 1463: 1458: 1453: 1449: 1445: 1441: 1434: 1426: 1422: 1417: 1412: 1409:(2): 185–93. 1408: 1404: 1400: 1393: 1385: 1381: 1376: 1371: 1368:(2): 249–64. 1367: 1363: 1362:Biostatistics 1359: 1355: 1349: 1335: 1331: 1325: 1317: 1313: 1308: 1303: 1299: 1295: 1291: 1287: 1283: 1279: 1275: 1268: 1254: 1248: 1233: 1229: 1223: 1209: 1203: 1188: 1181: 1173: 1169: 1164: 1159: 1154: 1149: 1145: 1141: 1137: 1130: 1128: 1123: 1113: 1110: 1108: 1105: 1103: 1100: 1098: 1095: 1094: 1088: 1079: 1077: 1073: 1062: 1045: 1042: 1035: 1032: 1029: 1026: 1023: 1022: 1008: 1002: 1001: 999: 998: 989: 986: 983: 980: 977: 976: 975: 972: 970: 966: 713: 673: 586: 584: 579: 574: 564: 559: 557: 552: 547: 535: 532: 529: 526: 523: 520: 517: 514: 509: 506: 503: 500: 499: 497: 494: 491: 488: 485: 482: 481: 480: 472: 463: 462: 460: 457: 454: 450: 447: 443: 442: 433: 429: 426: 423: 420: 416: 415: 409: 407: 403: 399: 395: 391: 387: 383: 379: 372: 367: 365: 361: 357: 353: 349: 345: 341: 337: 330: 321: 319: 315: 310: 306: 305:Gene Ontology 302: 298: 294: 290: 280: 276: 274: 270: 266: 262: 251: 249: 245: 241: 237: 233: 227: 217: 211: 208: 204: 201: 200: 199: 197: 193: 189: 185: 181: 177: 171: 161: 159: 155: 145: 142: 131: 128: 120: 116: 113: 111: 107: 106:median polish 101: 99: 95: 84: 82: 78: 70: 66: 53: 49: 40: 38: 34: 30: 26: 18: 2552:. Retrieved 2548:the original 2538: 2527:. Retrieved 2518: 2507:. Retrieved 2498: 2471: 2467: 2457: 2420: 2416: 2406: 2369: 2365: 2355: 2318: 2314: 2304: 2259: 2255: 2184: 2180: 2114:. Retrieved 2110: 2101: 2090:. Retrieved 2081: 2070:. Retrieved 2066:the original 2056: 2045:. Retrieved 2041:the original 2031: 1996: 1992: 1982: 1971:. Retrieved 1962: 1951:. Retrieved 1942: 1936: 1925:. Retrieved 1916: 1905:. Retrieved 1901:the original 1891: 1880:. Retrieved 1871: 1862: 1853: 1816: 1812: 1762: 1758: 1710: 1706: 1700: 1681: 1675: 1642: 1638: 1632: 1597: 1593: 1566: 1539: 1535: 1525: 1498: 1494: 1484: 1447: 1443: 1433: 1406: 1402: 1392: 1365: 1361: 1354:Irizarry, RA 1348: 1337:. Retrieved 1333: 1324: 1281: 1277: 1267: 1256:. Retrieved 1247: 1236:. Retrieved 1232:the original 1222: 1211:. Retrieved 1202: 1191:. Retrieved 1180: 1143: 1139: 1085: 1068: 1059: 1019:SAM features 973: 969:Fold changes 968: 967: 587: 582: 577: 569: 562: 560: 548: 544: 533: 527: 521: 515: 507: 501: 495: 489: 484:Quantitative 483: 478: 470: 465:recommended; 456:Permutations 394:permutations 381: 374: 368: 335: 334: 285: 269:Bioconductor 257: 231: 229: 215: 173: 151: 137: 125: 114: 102: 90: 74: 46: 43:Introduction 28: 24: 23: 2636:Microarrays 1999:(r5): rs5. 1993:Sci. Signal 1078:(Genowiz). 528:Time course 439:Running SAM 348:Gilbert Chu 176:homogeneous 33:microarrays 2630:Categories 2554:2009-04-02 2529:2008-01-02 2509:2008-01-01 2116:2023-11-24 2092:2008-10-15 2072:2007-12-31 2047:2007-12-31 1973:2007-12-31 1953:2007-12-31 1927:2014-09-09 1907:2007-12-31 1882:2007-12-31 1819:(1): 497. 1339:2023-11-24 1278:Proteomics 1258:2008-01-01 1238:2008-01-02 1213:2008-01-02 1193:2007-12-26 1118:References 1112:Proteomics 1072:GeneSpring 516:Multiclass 431:Controller 419:microarray 406:Bonferroni 398:parametric 289:phenotypes 265:Moksiskaan 148:Clustering 77:Affymetrix 60:Techniques 2597:—software 2591:—software 2585:—software 2579:—software 2037:"DBI Web" 1334:MathWorks 1298:1615-9853 774:# 541:Algorithm 496:Two class 490:One class 364:R-package 318:neoplasms 248:k-medoids 240:k-medoids 2490:16076888 2449:15921534 2398:16872483 2347:17612399 2296:11309499 2203:17317331 2087:"RssGsc" 2023:23443684 1845:19038021 1791:24564555 1727:24334380 1659:17061323 1624:16964229 1558:16473874 1517:17646307 1476:21070630 1425:12538238 1384:12925520 1316:25690415 1172:16199517 1091:See also 522:Survival 502:Unpaired 417:Perform 236:centroid 2440:1173086 2423:: 129. 2389:1544358 2372:: 359. 2338:1931607 2321:: 242. 2264:Bibcode 2062:"SCOPE" 2014:3756668 1836:2632677 1782:4072854 1667:8192240 1615:3272078 1467:2998528 1450:: 553. 1307:4510819 1163:1239896 1074:), and 479:Types: 371:t-tests 301:GenBank 261:GenMAPP 244:k-means 141:t-tests 98:MA plot 81:Agilent 2488:  2447:  2437:  2396:  2386:  2345:  2335:  2294:  2284:  2201:  2021:  2011:  1859:"Home" 1843:  1833:  1789:  1779:  1735:760277 1733:  1725:  1688:  1665:  1657:  1622:  1612:  1556:  1515:  1474:  1464:  1423:  1382:  1314:  1304:  1296:  1170:  1160:  995:Output 917:  896:  878:  869:  831:  810:  786:  777:  771:  762:  726:  710:  698:  656:  641:  611:  508:Paired 362:in an 156:, and 37:genome 2287:33173 2252:(PDF) 1731:S2CID 1663:S2CID 452:Sizes 402:ANOVA 338:is a 207:UPGMA 2486:PMID 2445:PMID 2394:PMID 2343:PMID 2292:PMID 2199:PMID 2019:PMID 1841:PMID 1787:PMID 1723:PMID 1686:ISBN 1655:PMID 1620:PMID 1554:PMID 1513:PMID 1472:PMID 1421:PMID 1380:PMID 1312:PMID 1294:ISSN 1168:PMID 575:. r 561:The 404:and 346:and 263:and 186:and 79:and 2603:in 2476:doi 2435:PMC 2425:doi 2384:PMC 2374:doi 2333:PMC 2323:doi 2282:PMC 2272:doi 2189:doi 2009:PMC 2001:doi 1831:PMC 1821:doi 1777:PMC 1767:doi 1715:doi 1647:doi 1610:PMC 1602:doi 1544:doi 1503:doi 1462:PMC 1452:doi 1411:doi 1370:doi 1302:PMC 1286:doi 1158:PMC 1148:doi 1144:102 194:or 2632:: 2484:. 2472:21 2470:. 2466:. 2443:. 2433:. 2419:. 2415:. 2392:. 2382:. 2368:. 2364:. 2341:. 2331:. 2317:. 2313:. 2290:. 2280:. 2270:. 2260:98 2258:. 2254:. 2237:^ 2211:^ 2197:. 2185:40 2183:. 2179:. 2153:^ 2125:^ 2109:. 2017:. 2007:. 1995:. 1991:. 1861:. 1839:. 1829:. 1815:. 1811:. 1799:^ 1785:. 1775:. 1763:15 1761:. 1757:. 1743:^ 1729:. 1721:. 1711:10 1709:. 1661:. 1653:. 1643:24 1641:. 1618:. 1608:. 1598:24 1596:. 1592:. 1580:^ 1552:. 1540:22 1538:. 1534:. 1511:. 1499:23 1497:. 1493:. 1470:. 1460:. 1448:11 1446:. 1442:. 1419:. 1407:19 1405:. 1401:. 1378:. 1364:. 1360:. 1332:. 1310:. 1300:. 1292:. 1282:15 1280:. 1276:. 1166:. 1156:. 1142:. 1138:. 1126:^ 714:90 366:. 320:. 246:, 2557:. 2532:. 2512:. 2492:. 2478:: 2451:. 2427:: 2421:6 2400:. 2376:: 2370:7 2349:. 2325:: 2319:8 2298:. 2274:: 2266:: 2205:. 2191:: 2119:. 2095:. 2075:. 2050:. 2025:. 2003:: 1997:6 1976:. 1956:. 1930:. 1910:. 1885:. 1865:. 1847:. 1823:: 1817:9 1793:. 1769:: 1737:. 1717:: 1694:. 1669:. 1649:: 1626:. 1604:: 1574:. 1560:. 1546:: 1519:. 1505:: 1478:. 1454:: 1427:. 1413:: 1386:. 1372:: 1366:4 1342:. 1318:. 1288:: 1261:. 1241:. 1216:. 1196:. 1174:. 1150:: 1038:i 1011:y 1005:y 950:t 947:n 944:a 941:c 938:i 935:f 932:i 929:n 926:g 923:i 920:s 914:d 911:e 908:l 905:l 902:a 899:c 893:s 890:e 887:n 884:e 881:g 875:f 872:o 866:r 863:e 860:b 857:m 854:u 851:N 846:s 843:e 840:n 837:e 834:g 828:d 825:e 822:l 819:l 816:a 813:c 807:y 804:l 801:e 798:s 795:l 792:a 789:f 783:f 780:o 768:f 765:o 759:) 756:e 753:l 750:i 747:t 744:n 741:e 738:c 735:r 732:e 729:p 721:h 718:t 707:r 704:o 701:( 695:n 692:a 689:i 686:d 683:e 680:M 674:= 671:) 668:R 665:D 662:F 659:( 653:e 650:t 647:a 644:r 638:y 635:r 632:e 629:v 626:o 623:c 620:s 617:i 614:d 608:e 605:s 602:l 599:a 596:F 583:i 578:i 572:i 570:d 566:o 563:s 382:j 377:j 375:d 232:K 209:)

Index


microarrays
genome


National Center for Toxicological Research
Affymetrix
Agilent
local regression
MA plot
median polish
Quantile normalization

Factor analysis
t-tests
Hierarchical clustering
k-means clustering
Hierarchical clustering
homogeneous
distance matrix
Pearson's correlation
Spearman's correlation
Manhattan distance
Euclidean distance
UPGMA
k-means clustering
centroid
k-medoids
k-means
k-medoids

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