We need to draw blood from a patient and keep it in a test tube for analysis of blood corpuscles and plasma. We are provided with the following types of test tubes. Which of these will you not use for the purpose?
Test tube containing Calcium Chloride.
Clotting of blood can be prevented by adding heparin, one of the most powerful anticoagulants, which acts indirectly by activating plasma antithrombin III. Heparin is effective both in vivo and in vitro. EDTA and sodium citrate are also effective anticoagulants. Calcium on the other hand, is required for the clotting cascade of blood. Without calcium, blood cannot clot. So, use of a calcium compound will most definitely induce clotting. Hence, the answer is A.