In situ hybridization (ISH) is a technique that allow you to visualize a gene’s location. The location is typically determined at the level of the cell or tissue region. However, chromosome painting is also a form of in situ and has a better resolution. In general, if a scientist is talking about ‘in situs’ or WISH, they are referring to the form that shows where a gene is being expressed.
In situ hybridization is like a Google search, where the probe is our search term.
At the most basic level, ISH simply attaches a labeled probe of DNA or RNA (nucleic acids) to other DNA or RNA. You can think of in situs as the Google search of biology. In Google, you can search a variety of media (websites, videos, or images) based off whatever you put in the search box. Using in situs we can search the various forms of nucleic acids based off the probe whose sequence is known.
Thus, many different techniques with a variety of goals fall under the broad category of ISH. This can lead to a lot of confusion even within the field of biology. At a conference dinner I was discussing my work on developing FISH for sticklebacks and at least one PhD at the table thought I was talking about chromosome painting for most of the conversation until what I was saying stopped making any sense. So if you find this confusing, you are in good company.Continue reading