Hydrogen peroxide leads to rapid detachment of nef -expressing astrocytes. U251MG-parental and -Nef cells were treated with hydrogen peroxide (10 μM) for 30 min. Cells were subsequently washed twice with PBS, incubated in VLE-RPMI 1640 medium containing 10% FCS for a further 3 h 30 min and subsequently a light microscopic analysis of astrocytic cells was performed. A Zeiss Axiovert 25 microscope (Carl Zeiss Jena GmbH, Jena, Germany) was used. Original magnification, × 100.