Step-by-step protocol to perfuse and dissect the mouse parotid gland and isolation of high-quality RNA from murine and human parotid tissue

Macroscopic identification and surgical removal of the mouse parotid gland is demanding because of its anatomic location and size. Moreover, the mouse parotid gland contains high concentrations of RNases, making it difficult to isolate high-quality RNA. So far, appropriate methods for optimal perfusion-fixation and dissection of mouse parotid glands, as well as the isolation of high quality RNA from this tissue, are not available. Here we present a simple, optimized, step-by-step surgical method to perfuse and isolate murine parotid glands. We also compared two common RNA extraction methods (RNeasy Mini Kit versus TRIzol) for their yields of high-quality, intact RNA from human and murine parotid gland tissues that were either snap-frozen or immersed in RNA stabilization solution. Mouse parotid tissue that was perfused and immersed in RNA and human samples immersed in RNA exhibited the best RNA quality, independent of the isolation method.