Rats are used to make rat monoclonal anti mouse antibodies. There are less rat- than mouse clones however. Rats genes from rodents of the genus Rattus norvegicus are often studied in vivo as a model of human genes in Sprague-Dawley or Wistar rats.
Western Blot can be performed on tissues and cell extracts to determine the proteins present in your sample after PAGE electrophoresis and transfer on PVDF or Nitrocellulose. PVDF is more advised. The best detection method is using enhanced chemiluminescence or ECL.