Roof rats are the worst rodent pest in the state of Florida and most abundant. The Norway rat (Rattus norvegicus) that is familiar to most people is rare in Florida. Roof rats consume and destroy stored animal and human food, attack fruit crops, and take up residence in attics, soffits, hollow walls, and out-buildings.
1 The sperm brings in another 23 chromosomes to complement the 23 held in the egg to get to a total of 46 chromosomes - what all of us normal people have.  We know from in vitro fertilization studies that the egg is only capable of being fertilized for about 24 hours after ovulation.
Egg Retrieval and Fertilization. The egg retrieval procedure is performed 34 to 36 hours after the hCG injection was given. In this procedure, the surgeon inserts a needle through the vagina into the woman's ovary to remove the fluid from the follicles, which contains the mature eggs.bout 18 hours after this fertilization procedure, it is possible to determine if the egg or eggs have been fertilized and have begun to grow as embryos. They are incubated and observed over the next 2 to 3 days or longer.