Prof. Mahmoud Rushdi (Assiut University-Egypt)
Hematological analysis is concerned with the analysis of the cellular component of blood including tests that used for evaluation of erythrocytes, leucocytes and platelets. Blood sample for complete blood count (CBC) must be collected on EDTA as anticoagulant.
Evaluation of the erythrocytes picture involve measuring red blood cells (RBCs) count, hemoglobin concentration (Hb), hematocrit or packed cells volume (PCV), mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), mean corpuscular hemoglobin concentration (MCHC) and evaluation of erythrocytes morphology.
Leucocytes picture involve measuring total white blood cells (WBCs) count, absolute and relative differential leucocytes count and leucocytes morphology. Platelets picture include determination of platelets count, plateletcrit (PCT), mean platelet volume (MPV), large platelet concentration ration (LPCR) and platelet distribution width (LPCR).
Both manual and electronic methods can be used for analysis, the selection of the suitable methods for analysis is dependent on the frequency of hematological analysis, higher frequency of hematological analysis require electronic methods for analysis. Taking in consideration that error is higher in manual methods than others.
Erythrocytes picture
Red blood cells count can be measured using the hemocytometer or blood cells counter.
Hemoglobin concentration is measured using acid hematin method, spectrophotometer or blood cells counter.
Packed cells volume (amount of blood occupied by RBCS) is measured using microhematocrite, macrohematocrit or blood cells counter.
Mean corpuscular values including Mean corpuscular volume (MCV), Mean corpuscular hemoglobin (MCH), Mean corpuscular hemoglobin concentration (MCHC).
Red blood cells distribution width (RDW): Measure for the variation in RBCs size in the blood circulation.
Erythrocyte morphology: although most hematological analysis can be done using electronic blood cells counter, but erythrocytes morphology must be done using manual methods (Blood film).
Blood film examination for erythrocytes morphology must accompany erythrocyte picture, even the analysis was done using blood cells counter. Erythrocytes morphology include examination for size, shape and stain of RBCs.
Leucocytes picture
Leucocytes picture include both total and differential leucocytic count. Total WBCs count is done using hemocytometer or blood cells counter. The differential leucocytic count is done manually using blood film, which yield the relative count of individual leucocytes, the absolute count for the individual leucocytes is obtained by multiplying the relative count by the total leucocytic count.
Platelets picture
Platelets count is done using the hemocytometer or blood cells count. Also count can be done using the blood film (indirect method).
Plateletcrit (PCT): Refer to the amount of blood occupied by platelets.
Mean platelet volume (MPV): Refer to the average volume of platelet.
Platelets distribution width (PDW): Measure the variation in size of platelets in the blood circulation.
Large platelets concentration ratio (LPCR): Measure for the concentration of the large platelets in the blood circulation.