Abstract: Three methods were used to isolate nucleic acid from rat’s inner ear. The amount and the pureness of the isolated nucleic acid were analyzed by PCR and UV-spectrometer. The results indicate that the three methods all can prepare high-quality nucleic acid from rat’s inner ear：method of plasmid preparation is good for isolating mtDNA without nuclear DNA；the method with SDS-proteinase K is suitable for isolat-ing the total DNA；the method with Trizol is suitable for preparing total RNA, total DNA and protein.

Key words: Inner ear, Nucleic Acid, Preparation methods, PCR