Department of Chemistry and Centre for Research on Biomolecular Interactions, York University, Toronto, Ontario M3J 1P3, Canada.
Anal Chem. 2010 Oct 15;82(20):8637-41. doi: 10.1021/ac1018364.
Capillary electrophoresis (CE) serves as a platform for a large family of temperature-sensitive affinity methods. To control the electrolyte temperature, the heat generated during electrophoresis is removed by actively cooling the capillary. Short parts of the capillary, particularly at its inlet, are not actively cooled, however, and the electrolyte in this part is likely to be at an elevated temperature. Owing to their relatively short lengths, the noncooled parts have never been considered as a potential source of artifacts. Here we report for the first time that electrophoresis of the sample through the short noncooled capillary inlet can lead to large systematic errors in quantitative CE-based affinity analyses. Our findings suggest that the noncooled capillary inlet region, in spite of being short, is a source of significant artifacts that must be taken into consideration by developers and users of CE-based affinity methods. We propose a simple solution for this problem: moving the sample through the noncooled inlet into the cooled region by pressure or by a low-strength electric field to save it from exposure to the elevated temperature.
毛细管电泳（CE）是一大类温度敏感亲和方法的平台。为了控制电解质温度，电泳过程中产生的热量通过主动冷却毛细管来去除。然而，毛细管的短部分，特别是在入口处，没有被主动冷却，因此该部分的电解质可能处于升高的温度。由于它们的长度相对较短，未冷却部分从未被认为是产生伪影的潜在来源。在这里，我们首次报告称，通过短的未冷却毛细管入口进行样品电泳可能导致基于 CE 的定量亲和分析中的大系统误差。我们的研究结果表明，尽管未冷却的毛细管入口区域很短，但它是一个产生显著伪影的来源，这必须引起基于 CE 的亲和方法的开发者和使用者的重视。我们为此问题提出了一个简单的解决方案：通过压力或低强度电场将样品从未冷却入口处输送到冷却区域，使其免受高温影响。
