General introduction to RIPA
RIPA stands for Radio immunoprecipitation assay. Let’s start out by talking about what a radio immunoprecipitation assay is and why it is used. In general, an immunoprecipitation assay uses antibodies to pull a protein of interest. The “immuno” part refers to the antibody (a molecule of the immune system) and the “precipitation” refers to a substance coming out of solution. You can read about the immunoprecipitation protocol in our other article "immunoprecipitation protocol". The radio part of this refers to using isotope labeling to track molecules. In a RIPA assay you radiolabel an antigen so you can track it when it binds an antibody, while the antibody is used to precipitate the antigen.