Detection of cell death in articular chondrocytes after being subjected to a 3-tesla electromagnetic field. Sections from articular cartilage (n = 5) were assessed for cell death rate after exposure to a 3-tesla pulsed electromagnetic field (EMF) by using a direct TUNEL labeling assay and were compared with a control group (n = 5) that was left unexposed. Fluorescein-dUTP (green) and nuclear staining with 4',6-diamidino-2-phenylindole (DAPI; blue) reflect no difference in cell death rate between the control and the 'pulsed EMF' group. The figure shows one representative experiment. DNAse-1-treated articular cartilage served as positive control. Scale bars, 100 μm.