Change in hsp expression in response to low oxygen tension.

Eighteen melanoma cell lines were cultured under identical conditions in 2% and 20% O2. After five days the cell lines were harvested, stained with PE-conjugated hsp antibodies and protein expression assessed by flow cytometry. A Fluorescence Index was calculated (fold increase in mean fluorescence of the stained cells compared with the unstained cells) and was used as a comparative measure of protein expression.