What does "put their zinc fingers in your leucine zipper" imply?

[NewHopeR]

Context:

3. Labs are not conducive to sex.
Unless you work in a sex lab, which may or may not be a real thing, it’s unlikely you can convince anyone to crawl under your lab bench with you (“Just ignore the discarded pipette tips, baby”) and, as protein biophysicists say, put their zinc fingers in your leucine zipper. But hey, prove me wrong, people.

[BobSmith]

Context:

3. Labs are not conducive to sex.
Unless you work in a sex lab, which may or may not be a real thing, it’s unlikely you can convince anyone to crawl under your lab bench with you (“Just ignore the discarded pipette tips, baby”) and, as protein biophysicists say, put their zinc fingers in your leucine zipper. But hey, prove me wrong, people.

[not a biologist]

zinc finger

leucine zipper

It's a crude/crass play-on-words, where "finger" and "zipper" might suggest something sexual, when in fact they are legitimate terms used in biology.