The wide scope of Bioconductor means that there are a great number of classes and methods for accomplishing pretty much any bioinformatics workflow that you'd want to. Sometimes, though, it would be helpful to have an extra data slot or some other tweak to the tools that would help to simplify our lives. In this recipe, we're going to look at how to extend an existing class to include some extra information that is specific to our particular data. We'll look at extending the SummarizedExperiment class to add hypothetical barcode information—a type of metadata indicating some nucleotide tags that identify the sample that is included in the sequence read.