Laboratory item (4,4)
![Ross](/clue/static/ross-mug.min.png)
I believe the answer is:
test tube
'laboratory item' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for test tube that I've seen before include "Small glass cylinder with one end closed, used in laboratory" , "Lab equipment" , "part of an experiment" , "Laboratory experimental container" , "glass vessel" .)