
Once we have a sperm sample, it is processed to fertilise the eggs. On a culture plate we prepare several micro-drops where we will place the right concentration of sperm. Later, we place an egg in each of these micro-drops and, within hours, one of the sperm will penetrate the egg producing fertilisation. (This is the classic In Vitro Fertilisation method). This plate is left in the incubator at 37º C, a concentration of 6% of CO2 and high relative humidity (95%), wich are the same condiotions of the womb. 18-20 hours after insemination we check under the microscope if the eggs have been properly fertilised, in wich case they will be called embryo´s.