title: Precise quantification of haemoglobin in erythroid precursors and plasma.
abstract: BACKGROUND
  Haemoglobin (Hb) quantification in whole blood is possible by various spectrophotometric methods. However, determination of low-level Hb in erythroid precursors or haemolytic plasma is inaccurate because of contribution from light scatter and/or nonhaemoglobin components with overlapping absorbance. Therefore, this study developed a sole method allowing accurate spectrophotometric quantification of Hb at a low concentration range.
  
  
  METHODS
  Advantage was taken of the unique absorption spectra of carbon monoxide-Hb complex (COHb) as compared to oxyHb. The visible absorption spectra of samples were recorded prior and following carbon monoxide exposure. A difference extinction coefficient at the maximal difference absorption was used to calculate Hb concentrations.
  
  
  RESULTS
  Known amounts of Hb were added to mouse erythroleukaemia (MEL) cells lysate or plasma to yield known 'theoretical' concentrations. The concentrations were measured by the current and known methods. The current method was found much more accurate compared with previous methods specifically at low concentrations.
  
  
  CONCLUSIONS
  The method is valid for accurate quantification of Hb at a wide concentration range (>0.1 μm/L) in erythroid precursors or plasma and is optional for other biological fluids.
authors.affiliation: Department of Human Genetics and Biochemistry, Sackler Faculty of Medicine, Tel-Aviv University, Israel.
authors.forename: S
authors.initials: S
authors.lastname: Toobiak
authors.forename: E A
authors.initials: EA
authors.lastname: Sher
authors.forename: M
authors.initials: M
authors.lastname: Shaklai
authors.forename: N
authors.initials: N
authors.lastname: Shaklai
mesh_terms: D000818:Animals; D002248:Carbon Monoxide / Q000737:chemistry; D002263:Carboxyhemoglobin / Q000032:analysis; D002457:Cell Extracts / Q000737:chemistry; D045744:Cell Line, Tumor; D015672:Erythroid Precursor Cells / Q000737:chemistry*; D006454:Hemoglobins / Q000032:analysis* / Q000737:chemistry; D004915:Leukemia, Erythroblastic, Acute / Q000097:blood / Q000473:pathology; D051379:Mice; D015203:Reproducibility of Results; D013053:Spectrophotometry / Q000379:methods*
chemical_list: D002457:Cell Extracts; D006454:Hemoglobins; D002248:Carbon Monoxide; D002263:Carboxyhemoglobin