add a bit of a microorganism to something to allow it to grow more. You have likely heard the term used more in the immunological sense, where inoculation refers to introducing a part of a microbe like a viral protein or a weakened or inactivated microbe to a person through vaccination in order to get that person’s body to learn to recognize and mount an immune response against it. But in microbiology it refers to this growth thing. So, for example, we might take a bacterial colony from a plate and use it to inoculate some media (bacteria food) in a flask – this will allow the bacteria to grow more in suspension. And then we can take some of that starter growth and add a few mLs to larger flasks of media, inoculating that media to let more of the bacteria grow and then, once we have a bunch of it, using it to make (express) a protein of interest.