It was found that, in the presence of mannitol, the yield of SSB in N 2 saturated DNA solution was larger than that in air saturated solution so that the oxygen enhancement ratio (OER) of SSB became smaller than 1, which indicates the appearance of reverse oxygen effect of DNA SSB.
以凝胶电泳法研究了γ辐射引起质粒ＤＮＡ单链断裂（ＳＳＢ）的氧效应，发现含自由基清除剂———甘露醇的ＤＮＡ溶液在Ｎ２饱和条件下的ＳＳＢ产额大于空气饱和时的产额，使得ＳＳＢ的氧增比（ＯＥＲ）小于１，即ＤＮＡ之ＳＳＢ存在反向氧效应。