Question

A smear of blood from a healthy individual is stained with a nuclear stain called hematoxylin and then observed under a light microscope. Which of the following cell types would be highest in number?

(a) Neutrophils

(b) Lymphocytes

(c) Eosinophils

(d) Monocytes

Answer 1

Answer is : (a) Neutrophils

A smear of blood from a healthy individual if viewed under the microscope will show highest number of neutrophils. There are three types of blood cells in an individual, i.e. red blood cells (erythrocytes), white blood cells (leukocytes) and platelets (thrombocytes). RBCs and platelets are devoid of nucleus, thus are not stained by haematoxylin nuclear stain. Therefore, only WBCs are stained. In a healthy individual, there are five types of WBCs, i.e.neutrophils (accounts for 40-75% of leukocytes), eosinophils (1-6%), basophils (0-1%), lymphocytes (20-45%) and monocytes (2-10%).