Nano LC/MS ultratrace proteomic analysis using narrow bore porous layer open tubular based platform

Abstract

Liquid chromatography coupled to a mass spectrometer as detector (LC-MS) are important tools for modern sample analysis especially in protein characterization and complex biological sample profiling. One specific challenge in medical analysis is that for many human or animal samples, the total amount of sample that can be used for LC-MS analysis is generally very limited. As an example, circulating tumor cells (CTCs) are usually found in blood in the level of 10 cells/mL. Despite the limited availability of CTCs, they can be useful for early therapeutic diagnosis as well as leading to effective treatment by targeting the key components in certain diseases. As the need arises for more sensitive and more efficient analysis for complex bio-medical substances, separation and analytical science are rapidly developing. Among the advances, porous layer open tubular (PLOT) columns have demonstrated high sensitivity for the analysis of complex biological samples and good adaptability to the state-of-art nanoliter-scale separation hardware without the need of extremely high backpressure, making them ideal for ultratrace clinical sample analysis. The purpose of this dissertation is to develop a practical PLOT column-based preparation, separation and analysis for limited numbers of cells as low as few hundred and also to push the limit towards extreme trace amounts of sample with even lower cell numbers.