In many areas of application, key objectives of chemical separation and analysis are to minimize the sample quantity while maximizing the chemical information obtained. Increasing measurement sensitivity is especially critical for proteomics research, especially when processing trace samples and where multiple measurements are desired. A rich collection of technologies has been developed, but the resulting sensitivity remains insufficient for achieving in-depth coverage of proteomic samples as small as single cells. Here, we combine picoliter-scale liquid chromatography (picoLC) with mass spectrometry (MS) to address this issue. The picoLC employs a 2-μm-i.d. open tubular column to reduce the sample input needed to greatly increase the sensitivity achieved using electrospray ionization (ESI) with MS. With this picoLC-MS system, we show that we can identify ∼1000 proteins reliably using only 75 pg of tryptic peptides, representing a 10–100-fold sensitivity improvement compared with the state-of-the-art liquid chromatography (LC) or capillary electrophoresis (CE)-MS methods. PicoLC-MS extends the limit of separation science and is expected to be a powerful tool for single cell proteomics.

中文翻译：

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使用2-μm-id敞开式管状色谱柱的Picoflow液相色谱-质谱法用于超灵敏的自下而上的蛋白质组学。

在许多应用领域中，化学分离和分析的主要目标是最大程度地减少样品数量，同时最大化获得的化学信息。提高测量灵敏度对于蛋白质组学研究尤其重要，尤其是在处理痕量样品以及需要多次测量的地方。已经开发了丰富的技术，但是所产生的灵敏度仍然不足以实现对单个细胞这样小的蛋白质组样品的深入覆盖。在这里，我们将皮升级液相色谱（picoLC）与质谱（MS）结合使用以解决此问题。picoLC采用2-μm内径的敞开式管状色谱柱，可减少所需的样品输入量，从而大大提高了使用MS电喷雾电离（ESI）可获得的灵敏度。有了这个picoLC-MS系统，我们表明，仅使用75 pg的胰蛋白酶肽就能可靠地鉴定出约1000种蛋白质，与现有技术的液相色谱（LC）或毛细管电泳（CE）-MS相比，灵敏度提高了10-100倍方法。PicoLC-MS扩展了分离科学的极限，有望成为用于单细胞蛋白质组学的强大工具。