For the first time, a team headed by Professor Stefan Schlatt, at Muenster University in Germany, were able to grow sperm by using germ cells. These are the cells in testicles that are responsible for sperm production.
They grew the sperm by surrounding the germ cells in a special compound called agar jelly to create an environment similar to that found in testicles, the Telegraph reported.
"I believe it will eventually be possible to routinely grow human male sperm to order by extracting tissue containing germ cells from a man's testicle and stimulating sperm production in the laboratory," said Prof. Mahmoud Huleihel, who also grew the sperm at Israel's Ben Gurion University in Beersheba.
Now the scientists who made the discovery have begun experiments that will hopefully lead to the 'Holy Grail' - human sperm grown outside a man's body.
Professor Huleihel said his team were now working 'as quickly as possible' to reproduce their success in mice to help infertile men.
"We have already applied the same tests as we did with mice in the laboratory, using human cells, but as yet have not had success. We are confident that if it can be done in a mammal such as a mouse it can be done in humans," he stated.
"We are experimenting with a number of different compounds to get the germ cells to grow into sperm. And we believe it will be possible. And, hopefully, soon," he added.
The findings of the sperm trial have been revealed in a major scientific journal published by Nature.