What is the Difference Between Capillary Electrophoresis and Gel Electrophoresis?

Capillary electrophoresis and gel electrophoresis are both techniques used to separate biomolecules based on their charge, size, and shape. However, there are some differences between the two methods:

1. Sample Amount: Capillary electrophoresis systems typically require a smaller amount of sample than slab-gel systems, which can be beneficial when only a small amount of sample is available.
2. Separation Medium: Gel electrophoresis separates biomolecules using a porous gel matrix, while capillary electrophoresis separates analytes within a fused silica capillary.
3. Resolution: Capillary electrophoresis is a higher-resolution method than slab-gel electrophoresis due to the higher surface-to-volume ratio within the thin capillary tubes, which allows heat to dissipate more effectively. This enables the use of much higher voltages without causing the matrix to overheat.
4. Applications: Gel electrophoresis can be used as a preparative/purification technique, as samples can be recovered from slab gels with relative ease. Capillary electrophoresis, on the other hand, is used in various applications such as capillary zone electrophoresis (CZE), capillary gel electrophoresis (CGE), capillary isoelectric focusing (CIEF), capillary isotachophoresis (CITP), micellar electrokinetic capillary chromatography (MEKC), and capillary electrochromatography (CEC).
5. Throughput: Capillary electrophoresis offers higher throughput than gel electrophoresis, which can lead to cost savings in labor and reagents.
6. Susceptibility to Error: Gel electrophoresis is more susceptible to errors due to gel material impurities, human error during casting or handling, and overheating, which can cause the gel to distort and melt. Capillary electrophoresis, on the other hand, is susceptible to leakage and clogging.

Comparative Table: Capillary Electrophoresis vs Gel Electrophoresis

Here is a table comparing the differences between capillary electrophoresis and gel electrophoresis:

Capillary electrophoresis is a higher-resolution method than gel electrophoresis due to its higher surface-to-volume ratio, which allows for higher voltages to be used without causing the matrix to overheat. Gel electrophoresis uses agarose or polyacrylamide gels as the separation medium, while capillary electrophoresis uses narrow-diameter tubes filled with fluid or gel matrices. Capillary electrophoresis can also be considered more versatile due to the wider range of separation matrices that can be used.