IVF treatment. Light micrograph of a micro-needle (bottom) injecting human sperm into a human egg cell (centre). This technique used for in vitro fertilisation (IVF) is known as intracytoplasmic sperm injection (ICSI). The injected sperm fertilises the egg. The resulting zygote is then grown in the lab until it reaches an early stage of embryonic development. It is then implanted in the patient's uterus. IVF allows infertile couples to conceive a child. Magnification: x240 when printed at 10 centimetres wide.