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Managing Gene Expression Data in Objects

Microarray gene expression experiments are complex, containing data and information from various sources. The data and information from such an experiment is typically subdivided into four categories:

  • Measured expression data values

  • Sample metadata

  • Microarray feature metadata

  • Descriptions of experiment methods and conditions

In MATLAB®, you can represent all the previous data and information in an ExpressionSet object, which typically contains the following objects:

  • One ExptData object containing expression values from a microarray experiment in one or more DataMatrix objects

  • One MetaData object containing sample metadata in two dataset arrays

  • One MetaData object containing feature metadata in two dataset arrays

  • One MIAME object containing experiment descriptions

The following graphic illustrates a typical ExpressionSet object and its component objects.

Each element (DataMatrix object) in the ExpressionSet object has an element name. Also, there is always one DataMatrix object whose element name is Expressions.

An ExpressionSet object lets you store, manage, and subset the data from a microarray gene expression experiment. An ExpressionSet object includes properties and methods that let you access, retrieve, and change data, metadata, and other information about the microarray experiment. These properties and methods are useful to view and analyze the data. For a list of the properties and methods, see ExpressionSet class.

To learn more about constructing and using objects for microarray gene expression data and information, see: