Relation between the Length of Exposure to Alkali and Yield of Ribonucleic Acid from Plant-leaf Tissue

SUITABLE methods for extracting and identifying RNA from leaf tissues of deciduous trees are modifications of the Schmidt–Thannhauser technique 1 . Two such methods have been described 2,3 , one involving the use of 0.33 N potassium hydroxide for 18 h at 37° C, with the other extending the time to 20 h 0.57 N potassium hydroxide. Identification of UNA is made from spectrophotometric absorption at 260 mµ. after ion exchange purification.