In vitro fertilisation. Image 2 of 2. Light micrograph showing a needle injecting the DNA of a sperm into a human egg, during the process of in vitro fertilisation (IVF). At centre is the rounded egg. A micro-needle (at right) has penetrated the egg & is injecting the DNA genetic material of a single sperm cell. At left, a flat- nosed pipette is used to hold the egg steady while the needle is inserted. This technique ensures penetration and fertilisation of the egg. It has been used successfully at IVF centres around the world for the treatment of certain infertility problems. See image M802/140 for needle about to inject the egg.