Our acoustic data give results similar to the acoustic wave velocities obtained by Kundu et al. for XTH2 cells using 1 GHz acoustic waves with a different analysis methodology (1500–1700 msÀ1) (34), and by Taggart et al. for a range of human-derived cells (1522–1537 msÀ1) using 40 MHz acoustic waves (49). Our improved analytical method uses phase information and has been shown to reduce the scatter and uncertainty in the acoustic wave velocity compared with other published methods, hence explaining the lower levels of experimental scatter when our data are compared with those of Kundu or Taggart (37). We note that the addition of Y-27632 does not significantly change the acoustic wave velocity (p ¼ 0.3).