I failed searching on Google technical details about how in-vitro fertilization is achieved. I'm referring to the toolset and its use, rather than the chemical or biological aspects of the process. I often watch on TV how a needle penetrates into a human egg to fertilize it with sperm, but provided that a human egg sizes about 100 microns, I come up with the following questions:

  • Do there really exist needles so thin to penetrate a 100 micron cell? In such case, how are these needles manipulated without breaking or losing them in the lab?

  • How do technicians manipulate the needle with such micrometric precision?

  • How do technicians keep the human egg still so they can break into it with the needle without pushing the egg away?

Not sure if these questions sound naive, but I haven't been able to find any simple answer to them on the Internet.

  • 2
    $\begingroup$ Have you read the Wikipedia article on Microinjection and followed up the references there? Remember the word needle does not imply any particular material or mode of construction, and of course the first needles were used for sewing (rather than injection) and made of bone. $\endgroup$
    – David
    May 14, 2020 at 10:09
  • $\begingroup$ @David, thank you! Actually Google never dumped the result for this Wikipedia's page and I also didn't come up with the "microinjection" word. I will check it out and follow up the references. Thx again! $\endgroup$
    – Claudi
    May 14, 2020 at 10:14

1 Answer 1


After following user David's hints, I have collected some videos that answer the questions I posted:

  • Regarding to needle manufacturing, there exist machines able to create micropipettes (this is how the needles are actually called) by heating glass cilinders and pulling them to create very thin tubes (capillaries). Click for featuring video.

  • Regarding to the high-precision manipulation, technicians use mechanical devices able to convert macroscopic motion (eg: human manipulation) to microscopic motion (eg: using reduction gears). Click for featuring video.

  • Regarding to how they keep the egg still, technicians use another type of pipette that slightly "sucks" the egg in a vaccuum-cleaner style. For a full-feature video of how the egg and sperm are manipulated, check this video out.


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