蛋白质的微芯片电泳分离及其与脱氧核糖核酸迁移规律的比较

在自制的聚二甲基硅氧烷(PDMS)微芯片上,使用十二烷基磺酸钠(SDS)无胶筛分电泳分离体系(10 g/L的羟乙基纤维素(HEC), 1 g/L的SDS, 40 mmol/L磷酸盐缓冲溶液,pH 7.0),采用在线自校正激光诱导荧光检测方法,在6.4 min内高效分离了异硫氰酸荧光素(FITC)衍生的6种蛋白质标准样品,连续6次电泳所得迁移时间的相对标准偏差(RSD)均小于10%。用自主建立的脱氧核糖核酸(DNA)定量分离模型对蛋白质迁移数据进行拟合,发现SDS-蛋白质复合物迁移规律与DNA相似,但迁移淌度与相对分子质量及电场强度之间的线性关系明显变差,可见原DNA分离模型要扩展到蛋白质范围必须对一些参数进行校正。

Separation of proteins on microchip electrophoresis and its comparison with DNA migration

The efficient separation of six standard proteins on a home-made poly(dimethylsiloxane) microchip with an auto-deducting background diode laser induced fluorescence detector was accomplished within 6.4 min under the sieving matrix of 10 g/L hydroxyethyl cellulose (HEC), 1 g/L sodium dodecyl sulphonate (SDS), 40 mmol/L phosphate buffer at pH 7.0. The experimental results showed that the reproducibility of protein separation was satisfactory and the relative standard deviations (RSDs) of protein migration time were less than 10%. The migration times of the proteins are analyzed by a quantitative mathematical model of deoxyribonucleic acid (DNA) proposed by ourselves previously. The results showed that the migration character of SDS-protein complexes was similar with DNA. However, the linear relationships between the mobilities of SDS-protein complexes and their relative molecular mass as well as electric field strength became worse, which indicated the mathematical model for DNA separation should be revised before it is used for protein separation.