1. Purification of anionic fluorescent probes through precise fraction collection with a two-point detection system using multiple-stacking preparative capillary transient isotachophoresis.
- Author
-
Haraga T, Tsujimura H, Miyauchi S, Kamimura T, Shibukawa M, and Saito S
- Subjects
- Anions, Aptamers, Nucleotide, Electrophoresis, Capillary methods, Fluorescent Dyes chemistry, Fluorescent Dyes isolation & purification, Isotachophoresis methods
- Abstract
A novel combination of CE-based separation techniques was used for the precise fractionation of ionic compounds from impurities. The combination of on-capillary concentration and separation using transient isotachophoresis, with multiple injections and a two-point detection system provided higher efficiency, and accuracy at a microliter-scale injection volume, than when CE was individually used for purification. In this paper, we present successful applications of the CE fractionation techniques for the purification of fluorescein, fluorescein-4-isothiocyanate, two fluorescent metal ion probes, and a fluorescein-modified DNA aptamer. The purity of the isolated fluorescent probes ranged from 95 to 99%. Such high purity could not be achieved using chromatographic purification techniques. With relatively low dilution factors of 6-9, the purified probe solutions were practical for use as purified stock solutions. In addition, the fluorescein-modified DNA aptamer purified by our method was successfully used in a thrombin binding assay. The method developed was useful for the purification of anionic fluorescent reagents to be of ultratrace analytical grade for use with CE-LIF., (© 2020 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)
- Published
- 2020
- Full Text
- View/download PDF