Define the Estimation of Haemoglobin in Blood?

Several methods are used to determine haemoglobin. In these methods hemoglobin is measured as oxyhaemoglobin, carboxyhaemoglobin, cyanmethaemoglobin and acid and alkaline haemin by its oxygen carrying capacity and by its iron content. Out of all these techniques the cyanmethaemoglobin method is now accepted as the standard method for haemoglobin estimation. It is routinely used for all haemoglobin estimations and gives reproducible results.