Red top tube would be used. This color tube is also used for kidney and liver function tests, electrolytes(Na, K, Cl, C02), sometimes glucose and also iron levels.
Red or tiger top tube.
red
red top
red top (Plain sterile tube)
the color tube is either gray or red..
serum,tiger tube
green
I would use the semi-colored tube.
The color tube u would use for the Creatinine test is GREEN...
a lavender top tube
blue
red
red
Lavender