The most common and most likely answer to this crossword clue is the 4 plus 4 letter word STEM CELL
I've seen this crossword clue in Independent
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More clues leading to the result STEM CELL
- Contributor to replacement therapy to control market, it's said
- Check place one's locked up potent biological unit
- Curb coterie from which specialised units develop
- Potential biological research material may have a strange smell etc
- Check prisoner’s accommodation that is capable of differentiation
- Originating material for organisms hawk traps caught and gathered up
- Check mobile phone? It’s a little thing but capable of development
- My daughters can differentiate smell, etc at work
- It’s a function to generate specialised derivatives by differentiation
- Subject of research to stop terrorist group
Buddy explains!

The straight part
We know that "Potential biological research material" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case potential biological research material = stem cell.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.