Aoi Aki's Tsumasaki Ni Kourozu, which deals with mycology: http://www.mangago.zone/read-manga/tsumasaki_ni_kourozu/
Ike Reibun's Gingaku Hakase to Marmot is a hardcore yaoi sci-fi, but her scientists are not your ordinary researchers: http://www.mangago.zone/read-manga/gingaku_hakase_to_marmot/
Ichijou Lemon's Kokuin deals with a neuroscience research lab at a university, but the science is a contrived plot mechanism: http://www.mangago.zone/read-manga/kokuin/
Do you include forensic researchers or surgeons in your scientist group?
Geology (again, as a plot device): http://www.mangago.zone/read-manga/doubt_nishimura_shuuko/
Forensics/CSI: http://www.mangago.zone/read-manga/i_d/
Hmm, maybe you should read them before you thank me. I wish I had much more scientific examples to give you, but science-in-yaoi seems mainly to be connected to lab coat fetishes and a reason for men to share an enclosed space (laboratory) for long hours.
Come to think of it, Aoi Aki has written other stories about horticulturalists and botanists. And I vaguely recall a couple of manga where the subject of agricultural sciences was mentioned. There there is iffy food science aplenty in any manga (not yaoi or BL, though) that has to do with competitive cooking (Yakidate!JaPan, Addicted to Curry or Kitchen Goddess, for example.)
Not yaoi, but @mermaidlily made this list that you might find interesting just like I did. There are different disciplines as well, so you can chose :D
Does anyone know a great manga with a scientist on it? Yaoi, or any genre really. It'd be much a appreciated for a recommendation. (〜 ̄△ ̄)〜