The sedimentation tube is a modification of the Westergren tube and was designed to improve and facilitate the technic of blood sedimentation.
The tube is 250 mm. long, with an internal diameter of approximately 2.5 mm. It is graduated from zero to 200 mm. and has a capacity in the graduated area of approximately 1 cc.
Two styles are available: one with stopcock permanently attached and the other without stopcock but with a metal plug to seal the top of the tube. A separate stopcock is available for the latter. The upper end of the stopcock has a Luer slip so that any syringe with a Luer tip can be attached. A LuerLok syringe is recommended because the tip is much stronger. The smaller the capacity of the syringe, the better the control.
From 1.5 to 2 cc. of the blood is withdrawn into a test tube containing a