Haemoglobin is a protein found in red blood cells that carries oxygen from the lungs to the body's tissues and removes carbon dioxide. It is an essential component of the human body, and its concentration in the blood, known as haemoglobin concentration or haemoglobin level, is an important indicator of an individual's overall health. Haemoglobin estimation is a laboratory test that measures the concentration of haemoglobin in the blood.
There are several methods for haemoglobin estimation, including spectrophotometry, cyanmethaemoglobin method, and hemoglobinometry. Here, we will discuss the procedure for haemoglobin estimation using the cyanmethaemoglobin method.
Preparation: The first step in the haemoglobin estimation procedure is to collect a blood sample from the patient. This is typically done by inserting a needle into a vein in the arm and drawing a small amount of blood into a tube. The blood sample should be collected in a tube containing an anticoagulant, such as EDTA, to prevent clotting.
Dilution: Once the blood sample has been collected, it is usually diluted with a saline solution to obtain a more accurate result. The dilution factor will depend on the concentration of haemoglobin in the blood sample.
Addition of reagent: The next step is to add a reagent to the diluted blood sample. In the cyanmethaemoglobin method, the reagent is a solution of potassium ferricyanide and potassium cyanide. These chemicals react with haemoglobin in the blood sample to form cyanmethaemoglobin, a compound that absorbs light at a specific wavelength.
Measurement of absorbance: The absorbance of the solution is then measured using a spectrophotometer, a device that measures the amount of light absorbed by a sample at a specific wavelength. The absorbance is directly proportional to the concentration of haemoglobin in the blood sample.
Calculation of haemoglobin concentration: The haemoglobin concentration is then calculated using a formula that takes into account the dilution factor and the absorbance of the solution. The final result is expressed in grams of haemoglobin per deciliter of blood (g/dL).
It is important to note that the accuracy of haemoglobin estimation may be affected by several factors, such as the quality of the blood sample, the condition of the reagents, and the accuracy of the spectrophotometer. Therefore, it is essential to ensure that the laboratory equipment and reagents are properly calibrated and that the blood sample is collected and handled correctly.
In conclusion, haemoglobin estimation is a laboratory test that measures the concentration of haemoglobin in the blood. The cyanmethaemoglobin method is a common procedure for haemoglobin estimation, which involves collecting a blood sample, diluting it with a saline solution, adding a reagent, measuring the absorbance of the solution, and calculating the haemoglobin concentration. It is an important tool for diagnosing and monitoring various health conditions, including anaemia and other blood disorders.