2.6.2. Hematological Analysis

Hematocrit or erythrocyte pack cell volume was determined in whole blood. Fifteen microliters of freshly withdrawn blood were loaded into a microcapillary tube with anticoagulant to reach eight-tenths of the tube length. Then, plasticine was placed at the bottom of the tube at one-tenth of the tube length and centrifuged using a microhematocrit centrifugation machine (Suranaree Medical Equipment Co., Ltd., Nakhon Ratchasima, Thailand) at 12,000 rpm for 2 min. The percent hematocrit was read on a standard hematocrit chart (Suranaree Medical Equipment Co., Ltd., Nakhon Ratchasima, Thailand) and recorded.

Blood cell staining was performed immediately after sampling. In a vial, a 5 μL blood sample was eluted with 995 µL of Natt–Herricks staining solution (dilution ratio, 1:200) for at least 5 min. Fifteen microliters of mixed solution were loaded on a hemocytometer with 2 replicates. The total blood count and differentiated blood count containing red blood cells (RBCs) and white blood cells (WBCs) were implemented according to the procedure of a previous study [43].