A melting method for RNA extraction from the mucosal membrane of the mouse middle ear

Purpose: There is much confusion surrounding the methods of RNA extraction from the middle ear mucosa of mice. In this study, we worked to develop a “melting method,” which is faster, purer, and more reliable than other methods in common use. Materials and Methods: Thirty-two ears were used for this study. Light microscopy with hematoxylin-eosin staining of the bullae, scanning electron microscopy (SEM), spectrophotometer analysis, and reverse transcription polymerase chain reaction were performed before and after melting the half lateral bullae, which were detached from the temporal bone by using a lateral retroauricular approach. Results: Each resected half bulla contained a well distributed mucosal membrane. After a TRIzol melting duration of 10‒30 minutes, only mucosal marker (MUC5AC) was expressed without bony marker (total osteocalcin). The same results were determined from SEM. Conclusion: This melting method, compared with stripping and irrigation methods, is effective and offers an easier, more robust approach to extracting RNA from the middle ear mucosal membranes of mice.