Thal. major/ infant

Control pH 6.0 Application

Figure 8.6 Hemoglobin electrophoresis at pH 8.6 and pH 6.2.

120 Part II • Red Cell Disorders

Table 8.4 O Points to Consider

When Analyzing Alkaline Electrophoresis

• What is the strength of the band?

• Does your patient have a transfusion history?

carefully developed for their hospital setting. Equipment costs, technologist time, and the number of samples to be evaluated factor into the decision as to whether the quantitative technique will be performed on site or sent out to a reference laboratory.

Isoelectric Focusing

Isoelectric focusing (IEF) is the method of choice for most newborn screening in the United States. This refined electrophoretic procedure uses a pH range of between 3 and 10 in polyacrylamide gel. Within this pH range, hemoglobins will achieve their isoelectric point, their point of no net negative charge, and they will focus into sharp distinct bands. Because each hemoglobin is a protein with a distinct amino acid composition, clearly defined points are achieved. This procedure is especially useful when small amounts of abnormal hemoglobin need to be detected.26 The cost of equipment for IEF is prohibitive in most community hospital settings, but this technique has great value for large-batch analysis such as newborn screening performed in state health laboratories.

lives. In a perfect world, every African American individual would know their hemoglobin S status, because a union with another individual carrying sickle cell trait could produce a child affected with sickle cell anemia (1 in 4 chance). Generally, all health educators should encourage their African American students to be tested for the presence of sickle cell gene as part of their normal health screening.

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