9 out of 42
HB estimation is not done by (AIIMS NOV 2007)
Ans. D Wintrobe method
- Sahli’s method: Hb estimation by converting a known volume of blood into acid heamatin by addition of dilute HCl and subsequence comparison with a suitable standard
- Spectrophotometry: This involves the use of photoelectric colorimeter that measure the amount of light absorbed by a solution. The light used is these instrument is of limited wave band and this band is chosen to correspond with the part of the spectrum that is maximally absorbed by the solution being tested.
- The one that is commonly used is cyanmethemoglobin method. Here Hb is converted into cyanmethemoglobin by Drabkin’s reagent (NaHCO3, 1 gm potassium cyanide 50 mg, potassium ferric cyanide 200mg and distill water 1 litre)
- Wintrobe’s tube: This is for estimation of ESR and PCV and not for Hb