Cited by 13Gene expression and cancer classificationBioinformatics and Genomic NetworksGenomics and Phylogenetic Studies

Positional artifacts in microarrays: experimental verification and construction of COP, an automated detection tool

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Yu, H., Nguyen, K., Royce, T., Qian, J., Nelson, K., Snyder, M., Gerstein, M.·2006·Nucleic Acids Research

Abstract

Microarray technology is currently one of the most widely-used technologies in biology. Many studies focus on inferring the function of an unknown gene from its co-expressed genes. Here, we are able to show that there are two types of positional artifacts in microarray data introducing spurious correlations between genes. First, we find that genes that are close on the microarray chips tend to have higher correlations between their expression profiles. We call this the 'chip artifact'. Our calculations suggest that the carry-over during the printing process is one of the major sources of this type of artifact, which is later confirmed by our experiments. Based on our experiments, the measured intensity of a microarray spot contains 0.1% (for fully-hybridized spots) to 93% (for un-hybridized ones) of noise resulting from this artifact. Secondly, we, for the first time, show that genes that are close on the microtiter plates in microarray experiments also tend to have higher correlations. We call this the 'plate artifact'. Both types of artifacts exist with different severity in all cDNA microarray experiments that we analyzed. Therefore, we develop an automated web tool-COP (COrrelations by Positional artifacts) to detect these artifacts in microarray experiments. COP has been integrated with the microarray data normalization tool, ExpressYourself, which is available at http://bioinfo.mbb.yale.edu/ExpressYourself/. Together, the two can eliminate most of the common noises in microarray data.

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  • Positional effects due to technical variability manifest as distinct spatial patterns across rows, columns and edges in different plates.

    “In contrast, positional effects due to technical variability manifest as distinct spatial patterns across the rows, columns and edges in different plates, a common challenge in multi-well-based assays30–33.”

    From A statistical framework for high-content phenotypic profiling using cellular feature distributions (2022) · cites this paper as [31]

    In Results and Discussion, “Artifact related to positions on microtiter plates” (page unavailable), the paper reports artificially higher correlations among nearby plate positions, linked to cross-contamination, and notes an effect along the Y-direction. It does not describe distinct patterns across rows, columns, and edges of different plates. (LLM, conf=0.84)

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  • Positional effects (edge effects, row/column dependencies, or gradient artifacts) are a persistent factor in multi-well assays and microarray experiments.

    “First, positional effects (edge effects, row/column dependencies, or gradient artifacts) are a persistent factor in multi-well assays and microarray experiments30,31,52.”

    From A statistical framework for high-content phenotypic profiling using cellular feature distributions (2022) · cites this paper as [31]

    The Results and Discussion sections on plate artifacts and their consequences report positional artifacts in every microarray experiment examined, including effects associated with locations on microtiter plates. The paper does not establish that these effects persist across multi-well assays generally, or specifically document edge effects and gradient artifacts. (LLM, conf=0.85)

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Authors
Yu, H., Nguyen, K., Royce, T., Qian, J., Nelson, K., Snyder, M., & Gerstein, M.
Affiliations
Yale University (US)
Corresponding author
Gerstein, M.
Venue
Nucleic Acids Research
Published
2006-12-14
Volume
35
Issue
2
Pages
e8-e8
ISSN
  • 0305-1048 (ISSN-L)
  • 1362-4962
OpenAlex
W2146506607
Cited by
13
References
31
Citations by year
2023: 1 · 2022: 2 · 2017: 1 · 2016: 2 · 2015: 1 · 2013: 1 · 2012: 2
FWCI
0.27
Type
journal article
Language
en
Open access
Licence
cc-by-nc
Locations
  • Nucleic Acids Research (publishedVersion, cc-by-nc)
  • PubMed Central (publishedVersion, cc-by-nc)
  • PubMed (publishedVersion)
Funders
National Institutes of Health
Topics
  • Life Sciences › Biochemistry, Genetics and Molecular Biology › Molecular Biology › Gene expression and cancer classification
  • Life Sciences › Biochemistry, Genetics and Molecular Biology › Molecular Biology › Bioinformatics and Genomic Networks
  • Life Sciences › Biochemistry, Genetics and Molecular Biology › Molecular Biology › Genomics and Phylogenetic Studies
Keywords
microarray data, co-expression analysis, cDNA microarray, COP, data normalization
MeSH terms
Animals, Humans, Software, Artifacts, Internet, Oligonucleotide Array Sequence Analysis, Gene Expression Profiling

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