It depends on the test - each test has a different type of test tube top.
A test tube with a red top is used for hcg testing.
Tiger top
red top
serum,tiger tube
for insulin test red top tube require.
A test tube with a red top is used for hcg testing.
Green
lavender top
Tiger top
red top
serum,tiger tube
for insulin test red top tube require.
red
red
Tiger top?
lavender
red top