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Long‐term precision in capillary isoelectric focusing for protein analysis
Author(s) -
Suratman Adhitasari,
Wätzig Hermann
Publication year - 2008
Publication title -
journal of separation science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.72
H-Index - 102
eISSN - 1615-9314
pISSN - 1615-9306
DOI - 10.1002/jssc.200700678
Subject(s) - isoelectric focusing , chromatography , chemistry , myoglobin , hydrochloric acid , reproducibility , capillary electrophoresis , analytical chemistry (journal) , capillary action , repeatability , polyacrylamide , materials science , biochemistry , inorganic chemistry , polymer chemistry , composite material , enzyme
In order to improve precision in protein analysis, a new rinsing procedure with 3M hydrochloric acid was investigated for linear polyacrylamide‐coated capillaries used in isoelectric focusing. After each run the capillaries were rinsed with hydrochloric acid for 5 min, followed by water for 20 min (Δ p = 1030 mbar each). Myoglobin, β‐lactoglobulin, and ovalbumin were used as model proteins; the pH gradient was provided by Pharmalyte (pH 3–10). The resulting method was already successful in avoiding capillary blockages, even for long‐series protein measurements. Further improvements in precision have been obtained by avoiding a complete standstill of liquid within the capillary when the separation system was idle. Pressure (Δ p = 300 mbar or more) and high voltage (30 kV) were therefore also applied during storage within a measurement series. The reproducibility of migration time and peak area are further improved with RSD% less than 10% in a long‐term measurement ( n = 86).