This depends on the reason why you are not getting pregnant. If there is male factor infertility then microinjection (ICSI) is required. This is a procedure whereby a single sperm is injected into the egg using an instrument called micromanipulator. If infertility is due female factors, classical IVF is done where sperm at a certain concentration are added to the culture medium containing the eggs. Sperm fertilizes the egg in a natural manner.
We keep the embryos inside incubators. Incubators are temperature and pH controlled environments that mimic the human body. Each couples' embryos are allocated a special compartment in the incubator.