Hemoglobinopathy is an inherited disorder characterized by the structure and subunit abnormalities in the production of hemoglobin. These variants in globin formation can result in disorders such as sickle-cell anemia and thalassemias. It has been demonstrated that many hemoglobin variants can be isolated for identification by isoelectric focusing (IEF) on a thin layer of gel.
Detection of hemoglobin (Hb) variants is important as a diagnostic tool and for genetic counseling. Detecting hemoglobin S, C and E (Hb S, Hb C and Hb E ) is particularly important because each of these variants in their homozygous state produces clinically significant effects. Additionally, these variants are found as double heterozygous (Hb SC, Hb SE) that also produce disease states.
The preparation and separation of Hb is accomplished through the application of a Hb sample onto a precast agarose gel containing low molecular weight amphoteric molecules with varying isoelectric points. When an electric current is applied to the gel these molecules migrate through the gel to their isoelectric points along the gel, forming a stable pH gradient.
The Hb variants also migrate through the gel until they reach the area where their individual isoelectric points equal the corresponding pH on the gel. At this point, the charges on the variants are zero and migration ceases. The electric field counteracts diffusion and the Hb variant forms a discrete thin band.
The following specimens are acceptable:
Samples are accepted Monday through Friday. Overnight shipments should be sent Monday through Thursday. Please send samples, at room temperature or on wet or dry ice, along with the completed test requisition to:
Attention: HLA Laboratory
10101 SW Barbur Blvd, Suite 200
Portland, OR 97219