You are required to draw blood from a patient and to keep in it a test tube for analysis of blood cropuscles and plasma. You are also provided with the following four types of test tuebes. Which of them will you not use for the purpose.

Options

A. test tube containing calcium bicarbonate
B. chilled test tube
C. est tube containing heparin
D. test tube containing sodium oxalate

Answer

C

Explanation

Clotting of collected blood can be prevanted by-
coating test tubes with silicon(which producenon wettable surface similar in its smoothness to endothelial lining of blood vessels).
adding chelating agents (includes trisodium citrate, sodium oxalate and sodium EDTA) which remove calcium which is important for blood coagulation , prevant blood clotting.
adding Heparin , most powerful anticoagulant which acts indirectly by activating plasma antithrombin III. Heparin is effective both in vivo and in vitro . Whereas the option a, b and d are effective in vitro.
Heparinized blood is not suitable for blood counts (as it alters the shape of RBC ' s and WBC's which affects blood testing . ) Fragility testing and complement fixation tests . Hence (c) is the correct answer .