Procedures for Isolating Mitochondria and Mitochondrial DNA and RNA

Abstract

Mitochondrial yield is greatly influenced by the source of the plant parts used for the preparation. Cobs, young unpollinated ear shoots (within 2 days after the silks emerge from husk leaves), are excellent source materials for both mtDNA and RNA, as well as for mitochondria for in organetto protein synthesis experiments. Good mtDNA/RNA yields can also be obtained from tassels removed from the stalks at approximately the time that meiosis is taking place in the anthers. Mesocotyl and epicotyl regions of 3–5-day-old etiolated seedlings are reasonable sources, although the relative yields tend to be lower and extreme care must be taken to avoid bacterial and fungal contamination if the seedling mitochondria are to be used for in organetto protein synthesis studies. The procedures can also be easily adapted for tissue cultures, but the reader is referred to the excellent compilation of Hanson et al. (1985) for detailed protocols for cultured cells.