Table 1. Types of Electrophoresis.
| Type of Electrophoresis | Description | Use |
| Routine (zone) | The traditional clinical laboratory electrophoresis is performed on a rectangle-shaped slab gel. | Separation of proteins.
Some are used in separating nucleic acids. |
| High-resolution (HRE) | Routine electrophoresis using a high voltage. | Conditions where more protein resolution is needed, e.g., separation of CSF proteins to diagnose multiple sclerosis and light chains in urine for early detection of lymphoproliferative disorders such as multiple myeloma. |
Polyacrylamide (PAGE)
| Horizontal or vertical slabs or gel incorporated into vertical cylinders or rods. DNA of 100 base pairs (bp) or less can be separated. | Used to study individual proteins in serum, especially genetic variants and isoenzymes (polyacrylamide gel may yield 20 or more fractions). |
| Capillary (CE) | It combines electrophoresis and high-performance liquid chromatography. CE occurs in a thin, fused silica capillary tube with polyacrylamide or agarose gel. | Commonly used in the clinical laboratory. It is very rapid, efficient, easily automated, computerized, and requires only a microvolume of sample. |
| Isoelectric focusing (IEF) | The gel is infused with chemicals that make a pH gradient across the surface of the gel (ampholytes). Using very high voltage, proteins will then migrate to the point on the gel where they have no net charge, i.e., their isoelectric point.
| Separation of variant hemoglobins in prenatal screening and isoenzymes. Detection of oligoclonal bands in gamma-globulin. |
| Immunofixation | An agarose gel electrophoresis separates the proteins in a serum sample. Antiserum against the protein of interest is spread directly on the gel. The protein of interest precipitates in the gel matrix. The precipitated protein is stained after a wash step to remove other proteins. | Study protein antigens and their split products. Identify proteins found in multiple myeloma. |
| Pulsed-field | Fragment separation is achieved by alternately applying the power to different pairs of electrodes. The most common method alternates the positive and negative electrodes in cycles during electrophoresis. | Separates larger fragments of DNA (> 50 kilobases) that cannot be separated with AGE or PAGE in routine electrophoresis systems.
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| Two-Dimensional | Separating the sample with two distinct separation techniques or electrophoresis separations. The separated bands from one electrophoresis are resolved more with the second electrophoresis. IEF, followed by PAGE or AGE, is the most frequent two-dimensional electrophoresis. The gel from the IEF capillary is removed and placed across the PAGE or AGE gel slab at right angles for the second electrophoresis. | Most applications are in research fields. It is used to study families of proteins in proteomics and protein content in different types of cells. It is also used in genetics to examine differences in diseases, gene mutations, and bacterial DNA and to study tumor cells to detect malignancies. |
