Fig. 7. Displacement of bound sperm from the ZP in the presence of suphated and non-sulphated competitors (‘pulse-chase’ experiments). (A) Representative micrographs of (+/+) sperm bound to the ZP in (i) control eggs, (ii) eggs after 15 minutes incubation with 1 mg/ml fucoidan, (iii) eggs after 15 minutes incubation with 1 mg/ml suramin. Scale bar, 50 µm. (B,C) Representative results showing the mean number of sperm bound to the ZP during the 35 minutes chase period in the presence of various competitors as indicated, expressed as a percentage of parallel controls at each time point. Zero minutes is taken as 100%. All compounds were tested at 1 mg/ml and experiments repeated at least 3 times.