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Mass distribution, polydispersity and focusing properties of carrier ampholytes for IEF II: pH 4–6 intervals
Author(s) -
Simó Carolina,
Mendieta Martha Elena,
Antonioli Paolo,
Sebastiano Roberto,
Citterio Attilio,
Cifuentes Alejandro,
Peltre Gabriel,
Righetti Pier Giorgio
Publication year - 2006
Publication title -
electrophoresis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.666
H-Index - 158
eISSN - 1522-2683
pISSN - 0173-0835
DOI - 10.1002/elps.200600344
Subject(s) - dispersity , chromatography , chemistry , analytical chemistry (journal) , distribution (mathematics) , organic chemistry , mathematics , mathematical analysis
For studying the M r distribution and number of species in narrow‐range (2 pH‐unit wide, in the nominal p I 4–6 interval) carrier ampholytes from four commercial sources (Bio‐Lyte, Servalyt, Ampholine and Pharmalyte), a 2‐D technique was adopted consisting of a focusing step in a liquid phase (Rotofor, yielding 20 fractions) followed by orthogonal CE in both, acidic and basic buffers. As a final step, every other fraction was analyzed by CE‐MS. The findings: Ampholine contains 80 different M r compounds, in the M r interval 203 to 893 Da, for a total of 325 isoforms. Bio‐Lyte consists of 66 different M r species, in the M r range 388 to 835 Da, for a total of 436 isoforms. Servalyt is made of 199 different M r compounds, in the M r interval 204 to 907 Da, for a total of 1302 isoforms. Pharmalyte pH 4–6.5, comprises 217 amphoteres, in the M r range 150 to 1179 Da, for a total of 812 isoforms. Pharmalyte appears to be the best brand, with the vast majority of species focusing sharply at their p I position and <5% “poor” species, distributed along the entire pH gradient, denoting an extremely shallow pH/mobility curve across the p I value.