What agents are used to bind target proteins in Western blotting?

In Western blotting, antibodies are the primary agents used to bind target proteins. This technique exploits the specificity of antibodies for their corresponding antigens. Once proteins are separated by size using gel electrophoresis and then transferred onto a membrane, the next step involves incubating this membrane with antibodies that specifically recognize and bind to the protein of interest.

The chosen antibodies can be primary antibodies that directly bind to the target protein, followed by the use of secondary antibodies that recognize the primary antibodies and are often conjugated to a reporter enzyme or a fluorophore. This setup allows for the visualization and quantification of the target protein through various detection methods, such as chemiluminescence or fluorescence.

Other options like enzymes, buffers, and salts play supportive roles in the process. Enzymes are often used for detection but do not bind directly to the target proteins. Buffers maintain the pH and ionic strength required for the binding reactions, while salts can help with protein solubility but are not the agents that specifically interact with the proteins of interest in the context of Western blotting. Thus, antibodies are the critical components for effectively capturing and visualizing target proteins in this technique.