Question: Can you artificially fertilize a human egg cell to make an embryo?

Paul McKeegan answered on 7 Nov 2017:

This depends on what you mean by artificial!

You can add lots of sperm to some eggs in a culture dish. This is In-Vitro Fertilisation, or IVF. I do this every week with cow eggs and sperm. Incubate for 24h and most of the eggs will be fertilised! Using cow eggs, about 80% tend to be fertilised and 20% are still developing after 7 days, which is as far as we can take them in the lab. The embryo cells divide about once every day, and on day 7 there can be up to 200 cells in what is called a blastocyst. But it is still a ball of cells and a long way from being a recognisable animal. Human embryos develop a little faster, and are blastocysts after around 5 days.

You can use a special microscope to do Intra-Cytoplasmic Sperm Injection (ICSI), which is what you see on the news whenever they talk about IVF treatment. You use one tool to hold the egg still, applying a gentle suction to it (like a plunger). Then you use a tiny needle to inject an individual sperm cell into the egg.

You can even do Somatic Cell Nuclear Transfer, which is where you take the nucleus out of an egg cell and replace it with a nucleus from a normal cell, then trick the egg into acting like it has been fertilised normally. This creates a clone and is how Dolly the sheep was made. It’s not very efficient, but the offspring produced to date seem to lead healthy lives! Of course, this is not allowed in humans!

If you mean can we use artificial sperm to fertilise an egg, this is a long way off, but many scientists are working on producing artificial cells to treat different diseases. Sperm and eggs will be much harder than most cells to make as they are so specialised, but it might be possible in a few decades. It would be a very impressive treatment for infertility. This would be very strictly regulated though, and might not be allowed at all if the public and the governments think it is a step too far!