Eggs were collected by hand stripping 10–12 h after a double
injection of CPE (the two injections totalling 3.5 mg/kg). The first
injection that is 10% of the total amount (0.35 mg/kg) was given
10 h before the second (3.15 mg/kg) injection of CPE [5]. Their
abdomens and urogenital papilla were dried before stripping. Samples
contaminated with fecal material or urine were discarded.
Only transparent, well rounded and unwrinkle eggs were used
for fertilization