> For the complete documentation index, see [llms.txt](https://khalil-lab.gitbook.io/evolver/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://khalil-lab.gitbook.io/evolver/extensions/custom-experiments/extractor-column.md). # Extractor Column ## Overview The two column extractor is a type of eVOLVER experiment designed to continuously extract a molecule of interest exuded by a microbe. One set of vials are bioreactors where cells are continuously cultured. Those vials are each paired with an extractor vial, where microbes are continuous dropped through a solvent layer that extracts a biomolecule of interest. This solvent can be sampled to determine amount of biomolecule that is made.