ESI-MS: The Future of Single-Cell Proteomics

Beijing University of Technology researchers, Xiayan Wang and Guangsheng Guo, recently published a review article in TrAC Trends in Analytical Chemistry discussing the technology development trend of electrospray ionization mass spectrometry (ESI-MS) for single-cell proteomics (1). The article highlights the recent progress made in the life sciences field, including the breakthroughs and advances in technologies that have contributed to the evolution of single-cell proteomics.

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Single-cell proteomics based on mass spectrometry (MS) has gained popularity over the last two decades due to its ability to identify low-abundance proteins and provide a theoretical basis for effective diagnosis, precise treatment, and the elucidation of disease mechanisms. ESI-MS offers the highest protein coverage for single-cell proteomics, but the sample throughput and coverage of single-cell proteomic technologies can vary greatly due to the availability of various pretreatment methods, separation techniques, and MS instrumentation.

ESI-MS is a powerful analytical tool for single-cell proteomics research. It works by ionizing proteins in solution and detecting their mass-to-charge ratios to identify their identity and quantity. ESI-MS has the advantage of high sensitivity and the ability to analyze small amounts of sample material. It is also capable of detecting a wide range of protein types, including those that are low in abundance. However, ESI-MS requires careful sample preparation and data analysis, and its performance can vary depending on the specific experimental conditions and instrumentation used.

The review article presents an overview of the different methods used for the separation of single-cell protein samples, including microscale chromatography, microfluidic devices, and droplet-based technologies. The performance of these methods in terms of detection coverage and throughput is also introduced. Microscale chromatography, which has been widely used in the separation and enrichment of proteins, offers high resolution and reproducibility, but it suffers from low sample throughput. Microfluidic devices, on the other hand, offer high sample throughput and can be integrated with other sample preparation and detection techniques, but they are still in the developmental stage. Droplet-based technologies, such as microdroplet-based proteomics and droplet digital polymerase chain reaction (PCR), offer high throughput, but they require complex instrumentation and are not yet widely used in single-cell proteomics.

The article also highlights the recent advances in ESI-MS instrumentation, including the development of nanospray ionization (NSI) and matrix-assisted laser desorption ionization (MALDI) techniques, which offer higher sensitivity and throughput, as well as the introduction of ion mobility spectrometry (IMS), which provides additional structural information about the analytes.

The review article concludes with an elaboration on the applications and development prospects of single-cell proteomics based on ESI-MS. Single-cell proteomics has the potential to revolutionize personalized medicine by providing more accurate and comprehensive information about individual cells, but it still faces many challenges, such as the limited amount of protein in single cells, the complexity of the proteome, and the lack of standardized protocols for sample preparation and analysis. With the development of new technologies and the collaboration between researchers in different fields, the future of single-cell proteomics based on ESI-MS looks promising.

Reference

(1) Wu, Y.; Zhang, W.; Zhao, Y.; Wan, X.; Guo, G. Technology development trend of electrospray ionization mass spectrometry for single-cell proteomics. Trends Analyt Chem 2023, 159, 116913. DOI: https://doi.org/10.1016/j.trac.2022.116913