Why is haemoglobin converted to cyanmet haemoglobin for the spectrophotometric assay?

Answer 1

When haemoglobin undergoes oxygenation, it changes colour, and this is what gives arterial blood its bright red colour. Since the absorption spectra of oxyhaemoglobin and deoxyhaemoglobin differ, the same concentration of a sample of haemoglobin can give different absorption readings depending on the degree of oxygenation. It is therefore necessary to convery haemoglobin into the stable non-oxygen binding form cyanmethaemoglobin before an accurate measurement can be made by spectrophotometric assay pooooo

Answer 2

Haemoglobin is converted to cyanmet haemoglobin for spectrophotometric assays because cyanmethemoglobin is more stable and has a stronger absorption peak that can be accurately measured at a wavelength of 540 nm, making it easier to quantify hemoglobin concentrations in a sample. Additionally, cyanmethemoglobin formation helps to eliminate interference from other substances in the sample that may affect the accuracy of the assay.