test tube
A cylindrical glass tube used in laboratory experiments.
試験管に溶液を入れて加熱した。
I put the solution into a test tube and heated it.
フラスコ is a wide-bodied flask used for holding or heating larger volumes of liquid, while 試験管 is a narrow test tube used for small samples or reactions.
test tube stand
test-tube baby
Compound of 試験 (test, experiment) and 管 (tube, pipe).