Western blots. (a) Proteins are subjected to electrophoresis, then transferred from the gel to a membrane. The membrane is washed successively with the first antibody and the second (labeled) antibody, allowing visualization of the protein of interest. (b) A Western blot shows levels of RecA protein in cells of the highly radiation-resistant bacterium Deinococcus radiodurans. The D. radiodurans protein DrRecA is first induced and then repressed, according to the need for DNA repair, in the hours following high-level irradiation.