Hemoglobin reference methods

Brunelle JA, Degtiarov AM, Moran RF, Race LA. Simultaneous measurement of total hemoglobin and its derivatives in blood using CO-oximeters Analytical principles their application in selecting analytical wavelengths and reference methods a comparison of the results and the choices made. Scand J Clin Lab Invest 1996 56,Suppl 224 47-69. 

Kobold U, Jeppsson JO, Duhfer T, Finke A, Hoelzel W, Miedema K. Candidate reference methods for hemoglobin Ale based on peptide mapping. Clin Chem 1997 43 1944-51. 

Mahoney, J.J. Vreman, H.J. Stevenson, D.K. Van Kessel, AL. (1993). Measurement of carboxihemoglobin and total hemoglobin by five sp>ecialized spiectrophotometers (CO-oximeters) in comp>arison with reference methods. Clinical Chemistry. 39/8, 1693-1700. 

The iron released may be measiu ed using a variety of methods based on two main techniques atomic absorption spectrometry (AAS) (flame or furnace) and ultraviolet (UV)-visible spectrophotometry. Flame AAS provides the reference method for determination of plasma iron. Protein precipitation with TCA is followed by centrifugation and measurement of iron in the supernatant by the absorption at 248.3 nm in an air-acetylene flame. While atomic absorption methods are routinely used for urine iron measurements, the need to remove protein and any hemoglobin contamination restricts the use of this technique in routine clinical chemistry for plasma iron. Electrothermal atomization AAS methods are typically used for determination of iron in tissues although inductively coupled plasma (ICP) is becoming more widely available. 

Reference method A reference method has been established that involves cleavage of hemoglobin into peptides by the endoproteinase Glu-C, followed by separation and quantitation of the hexapeptides by LC-electrospray ionization mass spectrometry or LC-capillary electrophoresis. 

Methods have also been developed for the demonstration of Hb-S within the red cell, and for that of ferrihemoglobin and CO-hemoglobin the reader is referred to (K14) and to references quoted in that review. 

Table 20-3 lists the principal plasma proteins and their half-lives, pi, molecular weights, and preferred method of analysis the individual proteins are listed in the order of their electrophoretic mobilities in agarose gels at pH 8.6. These proteins are described later in this chapter other chapters in this book describe many more proteins enzymes (see Chapter 21) lipoproteins (see Chapter 26) hormones (see Chapter 28) and hemoglobin, fibrinogen, and other coagulation proteins (see Chapter 31). The interim consensus reference intervals for 14 plasma proteins are listed in Table 20-4, pending the publication of more definitive intervals. . 

Hoelzel W, Weykamp C, Jeppsson JO et al (2004) IFCC reference system for measurement of hemoglobin Ale in human blood and the national standardization schemes in the United States, Japan, and Sweden a method-comparison study. Clin Chem 50 166-174... 

Magnetic ORD and CD. Applications of the anomalous dispersion of the Faraday effect for the study of proteins are still limited. For general experimental and theoretical aspects of MORD and MCD and further references see Refs. (42—49). [See below several investigations by these methods on myoglobin, hemoglobin or cytochrome c. ... 

In this section, the question raised above will be addressed by applying the local control methodology to a two-dimensional quantum model of the active site of hemoglobin. This system has been studied extensively for many years, both theoretically and experimentally, using a wide range of theoretical methods or experimental techniques. For a recent review of the theoretical approaches, see Ref. 144 and references therein. Here, we choose the six-coordinated iron-porphyrin-imidazole-CO (FeP(Im)-CO) as active site model, which recently has also been used for the study of the excited states [145]. In this complex, the imidazole mimics the proximal histidine, which binds to the central Fe atom and a second imidazole is placed in the proximity of the complex, to include the influence of the distal histidine. The respective configuration is sketched in Fig. 8. 

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