A drop of each of the following, is placed separately on four slides. Which of them will not coagulate?
A drop of each of the following, is placed separately on four slides. Which of them will not coagulate?
blood serum
sample from the thoracic duct of lymphatic system
whole blood from pulmonary vein
blood plasma.
Solution
Serum is the component of blood which does not play a role in clotting. Serum includes all proteins not used in blood clotting; all electrolytes, antibodies, antigens, hormones; and any exogenous substances (e.g., drugs or microorganisms).
Blood serum $=$ Blood $-($ cell + clotting factors)
Caution
Serum is the liquid that remains after the blood has clotted. Plasma is the liquid that remains when clotting is prevented with the addition of an anticoagulant.