Which of the following is NOT an advantage of capillary electrophoresis (CE)?

• A. Multiple samples can be assayed simultaneously on one injection
• B. Very small sample size
• C. Rapid analysis
• D. Use of traditional detectors

Answer: (A)

Capillary electrophoresis shines when you want fast separations with very small sample volumes, and these separations occur in a single capillary as a plug of sample moves past a fixed detector. Because only one sample is loaded into the capillary for a given run, you don’t get parallel analyses of multiple samples in a single injection. If you try to analyze several samples at once in the same injection, they would mix and you wouldn’t be able to tell which peaks came from which sample. To compare multiple samples, you perform successive injections or use a multi-capillary or microfluidic setup that provides parallel channels. So, the idea of assaying several samples simultaneously on one injection isn’t an inherent advantage of CE. The small sample requirement and the rapid analysis are genuine advantages, thanks to the high field strength and short separation paths in the capillary.