Improved separation of microheterogeneities and isoforms of proteins by capillary electrophoresis using segmental filling with SDS and PEO in the background electrolyte

Wei Lung Tseng, Yang Wei Lin, Huan Tsung Chang

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To improve the separation efficiency while achieving high sensitivity for the analysis of proteins' microheterogeneity, a segmental-filling technique has been developed and tested in capillary electrophoresis with laser-induced native fluorescence using a pulsed Nd:YAG laser. Using a short plug of SDS applied to the capillary and the anticonvectant poly(ethylene oxide) (PEO), the microheterogeneities of a number of proteins with pI values ranging from 4.5 to 11.1 could be detected. This high resolving power is due to reduced adsorption on the capillary wall, sieving, and the interaction with SDS. Consequently, the length and the concentration of the SDS plug play a significant role in determining the resolution and sensitivity. The method has been applied to the analysis of salivary and cerebrospinal fluid (CSF) samples. Without any sample pretreatment, using a 10-s 1 x SDS plug, six α-amylase isoforms in a salivary sample were resolved in 17 min and three more peaks were detected in a CSF sample. With simplicity, high resolving power, and rapidity, the method has shown great potential for proteomics.

Original languageEnglish
Pages (from-to)4828-4834
Number of pages7
JournalAnalytical Chemistry
Issue number18
Publication statusPublished - 2002 Sep 15


All Science Journal Classification (ASJC) codes

  • Analytical Chemistry

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