1. Relative Humidity Dependence of Single-Strand Breaks Induced by Drying in Plasmid DNA(Papers presented at the 38th Annual Meeting)

Abstract

pBR322 plasmid DNA purified with ethidium bromide-CsCl density gradient was dried at 30℃ under fixed relative humidities of 0, 12, 33, 43, 53, 76, 84, and 92%. Single-strand breaks (ssb) were most efficiently induced under 53% relative humidity but almost no ssb were induced below 12% and above 84%. At 53% relative humidity, most ssb were induced by drying during first 24 h and further drying induced little ssb. When air was replaced with nitrogen, the ssb induction was reduced.