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Erythrocyte Sedimentation Rate (ESR) : Significance, Mechanism, Influencing factors, Procedure

When anticoagulated blood is allowed to stand undisturbed condition for a period of time, the erythrocytes tends to sink to the bottom. Two layers are formed, the upper plasma layer and lower sedimented erythrocyte layer. The rate at which the red cells fall is knows as Erythrocyte Sedimentation Rate (ESR). Mechanism of sedimentation of RBCs : The ESR is consist of mainly four phases. These are aggregation, rouleaux formation, sedimentation and packing. 1st 15 minutes : Phase of minimum fall :  The red cells suspended in a column of citrated blood undergo rouleaux formation in the plasma and become heavier. Sedimentation in this phase is very low. 2nd 15 minutes : Phase of moderate falling :  Fibrinogen and globulin in the plasma develop fine threads and build up a network. The rouleaux of the red cells get tapped in the mash of network and become heaviest. It starts to settle Read More

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Hemoglobin Estimation : Significance, Reference Range, Procedure…..

Hemoglobin is a conjugated protein present inside the erythrocytes. Hemoglobin consist of  a prosthetic group named heam, which is  combined with protein called globin (Hemoglobin =  Heam + Globin). Other heam containing proteins in the body are Myoglobin, Cytochrome-C etc. Heam carries oxygen (O2) from the lungs to the tissue cells and carbon dioxide (CO2), the gaseous waste product from the cells to the lungs. After the normal life span of RBC (over 120 days), the red cells are destroyed by the reticuloendothelial cells (specially in the spleen) and the components of the hemoglobin undergo metabolic degeneration. Several methods are available for the estimation of hemoglobin in the blood. These are: Acid heamatin method (Sahli’s method) Cyanmethemoglobin method. Alkaliheamatin method. Haldane’s Carboxyhemoglobin method. Oxyhemoglobin method. Former two methods are commonly used for determination of hemoglobin concentration. Clinical Significance : A decreased in hemoglobin concentration below normal range in an indication Read More

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Anticoagulants : Composition, Action, Merits & Demerits…..

Anticoagulants are the chemicals which prevent clotting of blood when mixed with blood in proper proportion. Action of Anticoagulants : Some anticoagulants prevent clotting of blood by precipitating ionic calcium (Ca++) in the plasma. Heparin act as an anti-thrombin to prevent the transformation of prothrombin to thrombin and thus prevent the formation of fibrin from fibrinogen. Anticoagulants used in Laboratory and in Blood Bank  : Following anticoagulants are uses in the laboratory for examination of blood.: Sodium Fluoride Heparin Ethyl Diamine Tetra Acetic acid (EDTA) Potassium ammonium oxalate (Double Oxalate) Sodium Citrate etc. Following anticoagulants are uses in the Blood Bank for preservation of blood components; these are generally not used in the haematological investigations. Acid Citrate Dextrose (ACD) Citrate Phosphate Dextrose (CPD) Citrate Phosphate Dextrose Adenine (CPDA) RBC suspension in saline, adenine, glucose and manitol mixture. etc. Merits & Demerits of Anticoagulants Sodium Fluoride : Composition : Di-sodium or Read More