Cell death events in unfertilized Xenopus eggs. Intracellular ATP content (a), ADP/ATP ratio (b), intracellular pH (c), and egg diameter (d) were monitored over 48 hours after ovulation. Intracellular pH in panel (c) was measured using spectrometric and fluorescent assays (closed and open circles, respectively). Bars in panel (c) represent the range of pH readings taken by two persons in double-blind trials and data in panel (d) are means ± SD obtained by measurement of five eggs.
Tokmakov et al. BMC Cell Biology 2011 12:56 doi:10.1186/1471-2121-12-56