| The stains acridine orange, ethidium bromide, azur II, eosin B, trypan blue, Giemsa solution and nitroblue tetrazolium were purchased from Sigma. |
| At the end of ultrasound exposure, cells were stained with trypan blue. |
| Low levels of positively stained trypan blue dye were demonstrated in all subject groups, consistent with high viability. |
| Cells remaining uncolored in a trypan blue solution were identified as viable. |
| An aliquot of the cell suspension was removed and the number of viable cells determined by trypan blue exclusion. |
| Under each ultrasound condition, viability of cells was also assessed using trypan blue. |
